Perspective on Physical Therapist Management of Functional Constipation

Abstract

Functional constipation is a common bowel disorder leading to activity restrictions and reduced health-related quality of life. Typically, this condition is initially managed with prescription of laxatives or fiber supplementation, or both. However, these interventions are often ineffective and fail to address the underlying pathophysiology and impairments contributing to this condition. Physical therapists possess the knowledge and skills to diagnose and manage a wide range of musculoskeletal and motor coordination impairments that may contribute to functional constipation. Relevant anatomic, physiologic, and behavioral contributors to functional constipation are discussed with regard to specific constipation diagnoses. A framework for physical therapist examination of impairments that can affect gastrointestinal function, including postural, respiratory, musculoskeletal, neuromuscular, and behavioral impairments, is offered. Within the context of diagnosis-specific patient cases, multifaceted interventions are described as they relate to impairments underlying functional constipation type. The current state of evidence to support these interventions and patient recommendations is summarized. This perspective article aims not only to heighten physical therapists' awareness and management of this condition, but also to stimulate clinical questioning that will open avenues for future research to improve patient care.

Constipation is a symptom-based disorder characterized by “infrequent stools and/or difficulty with stool passage”^{1(p S8)} and reported by 1.9% to 27.2% of adults in the United States.^2,3 Although constipation has proven difficult to categorize due to its multifactorial pathophysiology, it is generally divided into 2 types: (1) primary constipation with functional impairment of the colon and anorectal structures and (2) secondary constipation related to organic or structural disease, systemic disease, or medications.⁴ Severe constipation has been defined as <1 bowel movement (BM) per week.⁵ Bowel movement frequency ≤1 time per week is reported more commonly by women, at a rate 3.5 times greater than that of men.⁶ Severe constipation also is quite common among individuals residing in nursing homes (44%–74%)^7–9 and in people who are postoperative for hip fracture,¹⁰ those with joint hypermobility,¹¹ and those with neurologic conditions.^12,13 In addition, the 2002 National Health Interview Survey revealed that individuals with back or neck pain reported a higher percentage of gastrointestinal conditions (inflammatory bowel disease, irritable bowel, or severe constipation) compared with those without such pain.¹⁴ Constipation also affects children (0.7%–29.6%),¹⁵ women who are pregnant (11%–38%),¹⁶ and young female athletes (29% nonintensive sport category and 36% intense sport category).¹⁷ Thus, it is quite likely that a physical therapist, regardless of practice specialty, will encounter patients troubled by constipation. Yet, individuals with constipation may not reveal this or other pelvic symptoms (urinary incontinence, fecal incontinence, pelvic organ prolapse, or pelvic pain) due to embarrassment or because they are seeking physical therapist services for another condition that they perceive to be unrelated.

Chronic constipation symptoms at any age can lead to reduced activity and work productivity. In addition, individuals with chronic constipation are more likely to utilize health care resources (physician and emergency department visits) compared with matched controls.¹⁸ Community-based studies indicate that the magnitude of health-related quality-of-life impact in adults with constipation is similar to that reported by those with diabetes, chronic allergies, dermatitis, and osteoarthritis.¹⁹ For studies of hospital-based adults, the impact was comparable to and overall greater than that felt by people with unstable Crohn disease, functional dyspepsia, and rheumatologic conditions.¹⁹ In the pediatric population, children with constipation reported worse health-related quality-of-life impact than that of peers with inflammatory bowel disease and gastroesophageal reflux disease. In addition, parents consistently rated quality-of-life impact associated with their child's constipation to a greater degree than their own child's rating.¹⁹

A systematic review of the epidemiology of constipation in children and adults showed that there is an increased tendency toward constipation with age; sex (female adults); lower social, economic, and education level, possibly related to diet and lifestyle habits associated with low socioeconomic status; high body mass index; and reduced mobility or low self-reported physical activity.¹⁵ Additionally, the review identified at least one study¹⁵ supporting the following risk factors: low consumption of fruit, vegetables, and fiber; living in a highly densely populated community; family history of constipation; and anxiety, stressful life events, and depression.

The high prevalence of constipation, the breadth of individuals substantially affected by this condition, and risk factors that may be modifiable through education and physical exercise render the topic of constipation relevant to physical therapists in all areas of practice. Although the role and responsibility of all physical therapists is to improve the overall health and function of their patients, we recognize that we cannot adequately address both adult and childhood constipation and all types of constipation in a single perspective article. Therefore, this perspective article focuses on adult functional constipation disorder only. This perspective article aims to increase physical therapists' knowledge and ability to recognize, diagnose, and make management decisions (intervene with most appropriate evidence-based physical therapy interventions or referral to a specialist physician or physical therapist, or both) for those individuals with functional constipation. This article also aims to describe the nomenclature and pathophysiology of constipation, briefly discuss the medical management of constipation, and provide a comprehensive, evidence-based guide to the physical therapist management of constipation.

Nomenclature and Pathophysiology

Functional (idiopathic) constipation presents no identifiable biochemical or direct structural cause for change in stooling patterns,⁴ but rather indicates that the interactive physiology (or function) of these anatomical structures is impaired.²⁰ Experts have worked to establish symptom-based classification schemes (eg, Rome III diagnostic criteria²¹) to best define functional constipation and related functional defecation disorders (DD) to direct medical management. According to the Rome III diagnostic criteria, a diagnosis of functional constipation must include the presence of ≥2 of the following criteria during at least 25% of defecations: straining to defecate, lumpy or hard stools, sensation of incomplete evacuation, sensation of anorectal obstruction or blockage, digital maneuvers to defecate, and <3 BMs per week. In addition, the diagnosis must include that loose stools are rarely present without use of laxatives, there are insufficient criteria for irritable bowel syndrome, and the criteria must be present for the past 3 months, with symptom onset at least 6 months prior to diagnosis. Although no one classification scheme fits all patients, these criteria appear to be widely accepted and provide a framework for further understanding.⁴

Functional constipation can be further divided into 3 general subgroups: normal transit constipation (NTC), slow transit constipation (STC), and DD (Fig. 1).^4,22 Defecation disorders can coexist with NTC and STC. Studies have shown that 40% to 50% of patients with DD also experience STC.²³

Figure 1.

Type of constipation, characteristics, and etiology.^{1,3,4,22,24,26,30,32–36,38} Two types of constipation are illustrated: (1) primary or functional constipation and (2) secondary constipation. There are 3 subtypes of functional constipation: normal transit (NTC), slow transit (STC), and defecation disorders (DD). Characteristics and associated etiology are presented in the figure. Irritable bowel syndrome-constipation dominant (IBS-C) can overlap with NTC. PR-LA=puborectalis muscle of the levator ani muscle, EAS=external anal sphincter.

Slow transit constipation is characterized by infrequent urges to defecate, abdominal pain, and distension²² and is most commonly seen in younger women, with symptom onset at puberty.²⁴ Normally, each day, 1.5 L of fluid enters the colon, but only 200 to 400 mL of this fluid is excreted in order to preserve fluid and electrolyte homeostasis in the body. With slowed movement of stool through the colon, an excessive amount of fluid is reabsorbed from the lumen of the colon, leading to hard stool and difficulty with evacuation. Slow transit constipation is generally found to be an autonomically driven neuromuscular disorder of the colon with both local and central triggers, including stress and disturbed sleep, pharmacology (opioids, antacids, antidepressants, antihistamines, blood pressure medications, iron and calcium supplements), and impaired function of the colonic pacemaker cells of Cajal.^25,26 In healthy humans, rectal distension has been found to reduce colonic motor activity via a viscerovisceral reflex called the rectocolonic inhibitory reflex.²⁷ Persistent rectal distension associated with disordered defecation has been linked to STC.^3,28 In addition, rectal distension has been associated with blunting of peristalic triggers, including waking, eating, and drinking.²⁹

Defecation disorders (also termed “outlet obstruction”) are characterized by difficult defecation associated with straining, longer toileting time to produce a BM, and manual assistance to complete rectal emptying (posterior vaginal wall/perineal splinting or anal digitation).^3,30 The Rome III criteria also describe the disorder.³¹ Contributors to DD may include dyssynergic defecation (uncoordinated or nonrelaxing external anal sphincter [EAS] and puborectalis muscle of the levator ani muscle [PR-LA]); rectal hyposensitivity due to either afferent nerve dysfunction or excessive rectal wall distension, thus requiring larger stool volumes to trigger defecation; and insufficient rectoabdominal coordination to evacuate stool.^26,32–35 Disordered defecation may be a learned behavior created by repeatedly deferring defecation despite experiencing fecal urgency either for personal convenience or due to fear of painful BMs.³⁵ Fecal matter may then either remain in and subsequently distend the rectum or retropulse into the left colon where stool becomes hard and dry.³⁵

Normal colonic transit is characterized by normal colonic stool movement, but the individual perceives difficult defecation or hard stools. Patients also may experience increased rectal compliance/stretch along with reduced sensory awareness of stool in the rectum.³⁶ Normal transit constipation responds best to increased fiber and osmotic laxatives. Fiber and osmotic laxatives work by pulling water from the colon's mucosal lining into the lumen.³⁷ Increased distension and abdominal pain/discomfort may be reported, and NTC is often found to overlap with constipation-dominant irritable bowel syndrome.³⁸

Initial Medical Management

Individuals with constipation usually first seek help from their primary care physician for symptom resolution. First-line primary care management typically includes prescription of laxatives and advice to increase fiber intake.³⁹ However, in patients with constipation due to STC or DD, fiber intake of up to 30 g per day does not produce any symptom change.³⁷ In addition, one survey that aimed to assess patient satisfaction with traditional constipation therapies showed that 60% and 50% of the respondents were dissatisfied with over-the-counter and prescriptive laxatives, respectively, to provide symptom relief.⁴⁰ These data call into question both the efficacy and cost-effectiveness of fiber and laxative interventions as the sole management of functional constipation, leaving >50% of the participants in this study with inadequate management. That is, these interventions fail to address major impairments underlying this condition (ie, motor incoordination and poor anorectal sensory awareness).⁴⁰ Unfortunately, when such interventions fail over a period of months or years, patients may be deemed as refractory to medical management. As a result, more invasive medical procedures may be offered, including implantation of sacral stimulators or other more radical surgical interventions (colectomy).^41,42

Neuromuscular and Behavioral Management

First-line management of functional constipation should consider interventions that target neuromuscular impairments (sensory and motor coordination) and correct behaviors that are detrimental to overall health including bowel function. Not only does this approach have the potential to reduce the need for invasive or radical procedures, but it is holistic in that it considers other pelvic symptoms (urinary incontinence, fecal incontinence, pelvic organ prolapse)⁴³ that coexist in people with bowel disorders. Coexisting pelvic symptoms can be attributed to poor toileting habits. For example, studies have shown that 50% to 85% of women do not sit on, but hover over, public toilets due to cleanliness concerns.^44,45 This toileting position may interfere with relaxation of pelvic-floor and urinary sphincter muscles during micturition.⁴⁴ With regard to defecation, it has been shown that increasing the angle of hip flexion (in relaxed sitting) straightens the anorectal angle, opens the anal canal, and reduces anal canal resistance to ease stool evacuation.⁴⁶ Thus, standing or hovering over the toilet could lead to excessive straining during BMs and could contribute to the development of DD.

Other toileting habits may contribute to the development of concomitant female pelvic-floor disorders. In one study, excessive straining with BMs as a young adult was found to be more common among women with pelvic organ prolapse (61%) and women with urinary incontinence (30%) compared with controls (4%). In addition, 95% of the women with pelvic organ prolapse reported a current history of constipation compared with 11% of controls.⁴⁷ The relationships between excessive straining/constipation and other pelvic symptoms further illustrate the importance of toileting habit education. Other toilet habits, including failure to respond to the urge to defecate (too busy) or choosing to wait (until in the privacy of the home), are important to identify and to discuss with the patient. These habits can lead to stool retropulsion and worsening of the patient's condition.

The care of people with functional constipation requires a clinician who is knowledgeable and skilled in the diagnosis and management of a wide range of motor coordination, musculoskeletal, and movement impairments that may contribute to the underlying pathophysiology of this condition. Individuals with functional constipation will need to be taught the proper mechanics to expel stool. Other behaviors, including eating, fluid intake, and exercise, should be examined, evaluated, and managed with respect to their unique contribution to each patient's symptom cluster. Physical therapists are well suited with regard to the examination, diagnostic, and intervention skills, including those to reduce risk factors, necessary to treat patients with functional constipation.

History/Symptoms and Quality-of-Life Assessment

As mentioned previously, Rome III criteria for diagnosing functional constipation must include any 2 of the symptoms listed earlier. In addition,  Appendix 1 provides other pertinent questions to clarify symptoms and behaviors that may affect bowel function.^48,49 The Bristol Stool Form Scale,⁵⁰ a self-report tool for adults with functional gastrointestinal disorders, can be used to obtain stool form information. This tool has been shown to have a moderate correlation with colonic transit time, but not stool frequency, in adults with constipation.⁵¹

Past and current medical and surgical history, medications, and risk factor assessment for constipation should be queried. Lindberg et al⁵² provided an extensive list of possible causes and constipation-associated conditions. In women, it has been suggested that sexual and physical abuse history be elicited based on studies that showed an alarming percentage of women with constipation reported abuse.⁴⁸ Screening for “red flags” is important to determine whether the patient's symptoms are characteristic of functional constipation amenable to physical therapy interventions or of more serious conditions requiring referral to a physician. Suggested red flags are listed in  Appendix 1.^48,52,53

If a patient has difficulty fully describing bowel and coexisting pelvic symptoms, pelvic symptom severity, and quality-of-life and disability impact, several questionnaires are available to the physical therapist to obtain this information. These questionnaires can be used to assist the physical therapist in identifying the scope and impact of pelvic-floor dysfunction. In addition, these questionnaires are excellent measurement tools to determine intervention outcomes, as they have been extensively tested and recommended based on their psychometric properties. For symptoms and symptom severity, the Patient Assessment of Constipation–Symptom questionnaire⁵⁴ and the Constipation Severity Index⁵⁵ have been recommended.^56–58 The Patient Assessment of Constipation–Quality of Life^59–62 and Constipation-Related Quality of Life⁶³ questionnaires have been endorsed as excellent tools for measuring quality of life. The Constipation-Related Disability Scale may be useful to measure the extent of disability caused by constipation.⁶⁴ Due to the high co-occurrence (50%–80%) of coexisting pelvic-floor disorders (urinary incontinence, fecal incontinence, pelvic organ prolapse, pelvic pain) and their potential to cause patient distress and reduced quality of life, we suggest using the Pelvic Floor Distress Inventory-Short Form-20 and the Pelvic Floor Impact Questionnaire, as they have been shown to be reliable and valid measures.^65–67

If the patient has been referred by a physician, it is important to ask whether a digital rectal examination or other diagnostic tests were performed. Digital rectal examination can identify a tear in the anal canal (anal fissure), creating excruciating pain with gentle palpation; polyps or masses; or rectal prolapse and is highly predictive for obstructive defection.^48,68 Blood testing, colonoscopy, or endoscopy is not routinely performed unless the physician suspects organic disease and the patient reports alarm symptoms.^22,52 However, tests for anorectal function, including balloon expulsion and anorectal manometry, may be performed. Balloon expulsion is a simple test to identify abnormal defecation patterns. It requires the patient to expel an artificial stool; often used is a water- or air-filled medical-grade balloon attached to a catheter with a 3-way stopcock and syringe to alter balloon pressures. However, test procedures lack standardization, and although the inability to expel the balloon suggests DD, a normal test does not exclude DD.⁴⁸ Anorectal manometry measures pressure activity in the anorectum and provides information including rectoanal reflexes, rectal sensation (hypersensitivity or hyposensitivity), rectal compliance, and the ability to generate adequate intra-abdominal force to expel stool along with contraction versus relaxation of the EAS and PR-LA. Like balloon expulsion, this test lacks standardization, yet is judged as having good evidence in favor of the test to identify DD, rectal hyposensitivity or hypersensitivity, and impaired compliance.⁴⁸

Colonic transit studies assess the speed that stool moves through the colon. There are several methods (radiopaque marker test, radioisotopes and scintigraphy, and wireless motility capsule) that can be used to measure colonic transit. Generally, depending on the site that markers accumulate, these tests can determine whether the patient has total or segmental colonic slow transit.⁵⁶ However, these tests also have been judged to lack standardization of methods and, particularly in the case of the wireless motility capsule, can be expensive and time-consuming to administer.^48,65 Colonic transit studies can have less utility in the presence of DD, as proximal colon function is commonly inhibited by evacuation disorders.^27,69 If these tests were not performed prior to physical therapy referral, the following situations may merit referral for anorectal testing and evaluation by a gastroenterologist: indeterminate physical therapist diagnosis and poor patient response to physical therapy intervention for a definitive physical therapist diagnosis.

Examination

If symptoms of functional constipation are identified by the physical therapist via the patient history or systems review, a physical therapist examination that includes a general neuromuscular screening, as well as specific thoracoabdominal,^48,70,71 lumbopelvic and hip, perineal and intrapelvic, and neurologic examinations, should be performed.^72–80 Appendix 2 specifies elements of the physical therapist examination for functional constipation disorders and associated impairments and their relationship to constipation symptoms to assist in physical therapist diagnosis. Elements of this examination that can be performed by the generalist physical therapist are noted in  Appendix 2.

The thoracoabdominal examination should highlight respiration, particularly diaphragmatic excursion, as it is often impaired in people with chronic low back pain or sacroiliac joint impairment.^76,77,81 Thoracic spine and rib mobility and static and dynamic postural habits are important to examine, as they can affect chest wall kinematics and breathing patterns⁸² essential to intra-abdominal force production required to effectively expel stool. A screen of the lumbar spine, pelvic ring, hip joints, and core stabilizers will identify impairments that might impede proper toilet positioning.⁷⁷ Assessment of myofascial tissues from T10 to thighs, including perineal and intrapelvic structures, will identify soft tissue impairments potentially affecting motor coordination.^72,76

Intervention

It is important for the physical therapist to accurately diagnose functional constipation type to guide intervention decisions. Commonly, patients will be referred for physical therapy with an unspecified constipation diagnosis. Also, a patient being treated for other issues may have concomitant constipation in need of physical therapy intervention. Such patients may not know or recall the underlying cause for their symptoms or be able to provide a full history of symptoms and symptom impact. In this case, a physical therapist without specialized knowledge may attempt to treat the patient based on a nonspecific diagnosis or fail to refer the patient to the appropriate health care professional.  Appendix 3 provides recommendations for referral to the appropriate health care professional based on specific symptoms.

Patients with constipation of differing etiology experience the same end results: difficulty with stool expulsion and similar life role impact. The disablement process associated with STC versus DD constipation type is illustrated in eFigure 1 (available at academic.oup.com/ptj) using the International Classification of Functioning, Disability and Health (ICF) model.⁸³ Despite differences in body structure and function, eFigure 1 shows how the impact on activity and participation and the influences of environmental and personal factors can be similar regardless of constipation diagnosis. However, because etiology for STC and DD differs, interventions aimed toward reducing changes in body structure and function need to be specific to constipation type, as described in the following cases.

Patient A

Patient A (STC type) is a 25-year-old woman (weight: 56.7 kg [125 lb], height: 167.6 cm [5 ft 6 in]) who reports infrequent urges to defecate, abdominal pain, and abdominal distension that began about 2 years previously but have worsened over time. She notes her inability to sense the urge to defecate following ingestion of a meal in the past 6 months. When she is able to defecate, she produces only small, separate, hard lumpy stools (Bristol Stool Form Scale type 2). Her colonic transit study demonstrated evidence of diffuse marker representation throughout the colon consistent with STC. Her social history revealed she has been employed as an elementary school teacher for the past 2 years. She admits to regularly skipping lunch and restricting her fluid intake to avoid having to empty her bladder and bowels at work. Because of her job responsibilities, she has little time to use the toilet. She uses public toilets only when she “can no longer hold it” because she fears coming in contact with germs. When she does use a public restroom, she will not sit, but hovers over the toilet. Her inability to defecate has led to anxiety (fear of not being able to have a BM) and depression (friends no longer invite her to dinner, as she has declined numerous invitations because eating increases her abdominal discomfort). Because of her changed social life, she spends evenings and weekends reading books and watching television. Physical therapist examination findings and interventions for patient A are listed in  Appendix 4.

Interventions for patient A (see  Appendix 4), including abdominal massage and lifestyle factor education and recommendations, are aimed at speeding movement of stool through the colon. Of these interventions, lifestyle education can be provided by the generalist physical therapist. Although lifestyle factor intervention can affect patient symptoms, additional intervention from a physical therapist specializing in pelvic-floor dysfunction may be necessary to obtain the best patient outcome.

Abdominal (colonic) massage is a noninvasive intervention for constipation management. Although exact mechanisms underlying its effects are not entirely clear, it is thought to stimulate peristalsis, decrease colonic transit time, and increase BM frequency.⁸⁴ Positive outcomes associated with this intervention in people with constipation have been described in single-case reports and a small number of randomized trials.^85–89

Although there is growing evidence to support the use of abdominal massage in the management of constipation, intervention parameters are not standardized.^85,88,89 In particular, the described massage form varies from light stroking⁸⁹ or kneading⁸⁴ alone to a combination of forms (stroking, effleurage, kneading, and vibration).⁸⁸ The massage typically starts at the base of the retroperitoneal ascending colon (right anterior iliac spine) and proceeds upward and in a clockwise direction across the intraperitoneal transverse colon, then downward over the descending colon (retroperitoneal in most patients) to the left anterior iliac spine and finally to the left ischium. The procedure is performed at a rate that takes 1 minute to complete and is repeated 10 times per session (eFig. 2, available at academic.oup.com/ptj). The procedure can easily be taught, thus empowering patients to manage their symptoms in both the short and long term. Acknowledged contraindications include bowel obstruction, abdominal mass, inflammatory intestinal disease, unstable spine, recent abdominal scarring, skin lesions, spastic colon due to irritable bowel syndrome, and recent radiation therapy (within 6 weeks).^88–91 However, associated side effects are unknown.^85,88

Education related to toileting habits is important in this case for several reasons. First, failing to respond to the urge to defecate could be a factor contributing to constipation. If defecation is delayed, colonic and rectal contractions that propel stool and the sensation of urgency subside as the rectum accommodates to continued distension.⁹² Stool retained in the colon will become hardened,⁹³ making it more difficult to expel at a later time. Second, hovering or standing over public toilets and poor toilet sitting posture will make expelling stools difficult or impossible. As mentioned previously, a posture of increased hip flexion facilitates defecation and reduces the need to strain.⁴⁶ This patient would be instructed to place a stool under her feet while sitting on the toilet to simulate the squat position. Third, it is important to assure patients that the normal defecatory frequency ranges from 3 times per day to 3 times per week.³ If a daily BM is expected and does not occur, the patient may become anxious and spend much of the day in the bathroom, straining excessively to produce stool.

A history positive for poor dietary choices, eating habits, and fluid intake would necessitate patient education or a referral to another health care provider to reduce their impact on patient A's bowel function. Poor diet (inadequate caloric, fiber, and fluid intake) and stool consistency (small, low-weight, and hard stools) are associated with slow colonic transit and difficult evacuation.^15,94 Alternately, diets containing sufficient fiber produce bulky, soft stools that move through the gut quickly.⁹⁵ The Academy of Nutrition and Dietetics recommends fiber intake of 14 g of total fiber per 1,000 kcal consumed (ranging from 21 to 25 g for women aged 19–70 years who are not pregnant and not lactating and ranging from 30 to 38 g for adult men aged 19–70 years).⁹⁶ These recommendations are based on levels protective against coronary heart disease. The Academy of Nutrition and Dietetics also recommends that fiber be obtained through plant foods, not supplements.⁹⁶ It is important to note that 90% of American children and adults do not meet daily fiber recommendations.⁹⁷ Also key is the finding that people with STC do not respond well to fiber intake ≥30 g per day.³⁷ Therefore, if patient A's dietary history includes meals that are infrequent, small, and seemingly fiber deficient, a referral to a dietitian should be made, as dietary intervention is important in this patient's plan of care.

Because fiber combines with water and ions in the colon,⁹⁸ monitoring of patient A's fluid intake is warranted. Data from a large epidemiologic study that examined the association between fiber and liquid intake to constipation showed low liquid intake alone to be a predictor of constipation in women.⁹⁹ There is limited evidence that increasing fluid beyond the daily (24-hour) recommended amount (approximately 2.7 L for women and 3.7 L for men ≥19 years of age)¹⁰⁰ will improve constipation.¹⁰¹ In addition, a general recommendation to increase fluids could have a deleterious effect in patients with coexisting bladder symptoms (urinary frequency and nocturia).¹⁰² Likewise, increasing fluid intake in older individuals with certain comorbid conditions (cardiac and renal disease) may be contraindicated.⁹

Finally, a recommendation to increase patient A's physical activity level may be indicated, as physical inactivity has been identified as a risk factor for constipation.¹⁵ However, few studies have examined the effect of physical exercise on colonic transit and symptoms in people with functional constipation. Based on this limited evidence, one review concluded that physical exercise is more likely to be beneficial in people with lack of exercise.¹⁰³ Any exercise recommendation targeted toward improving colonic transit also needs to consider the impact of exercise intensity. Low-intensity exercise may increase or have no effect on gastric emptying, whereas high-intensity exercise may delay gastric emptying.¹⁰⁴

Patient B

Patient B (DD type) is a 52-year-old woman who reports infrequent BMs, the need to strain excessively with every BM, a sense of incomplete emptying often following a BM, and the need to digitally evacuate stools occasionally. She inconsistently recognizes the urge to defecate. Her symptoms began after the delivery of her third child (at age 39 years), worsening over the past decade. She discussed her symptoms with her primary care provider and was referred to a gastroenterologist, who recommended an increase in fluid and fiber intake and prescribed a laxative. Despite years of following this regimen, her awareness of and capacity to expel stool did not improve. When previously employed as a cosmetic salesperson, she was permitted to leave her counter only during scheduled breaks. This situation caused her to experience hard, lumpy stools and painful BMs. As a result, she quit her job, and her attention over the past several years has been highly focused on having a BM. Her sexual relationship with her husband also has been impeded by discomfort caused by constipation. Because of the social impact of her symptoms, she has become depressed and feels hopeless. Examination findings and interventions for patient B are listed in  Appendix 4.

For patient B (DD type), physical therapy interventions are intended to teach skills and behaviors to promote the defecation process, including sensing stool entering the rectum, determining consistency of rectal contents (liquid, solid, or gas) in the sensate proximal anus, responding to the urge to defecate, sitting with optimal toileting posture, and coordinating relaxation of the EAS and PR-LA while the diaphragm and abdominal wall muscles generate sufficient intra-abdominal pressure assisting in stool expulsion (Fig. 2).^34,105–112 Specific physical therapy interventions for this patient include rectal sensory retraining; myofascial release to restricted tissues; muscle strengthening and retraining (abdominal wall, diaphragm, PR-LA, and EAS); abdominal, diaphragmatic, EAS, and PR-LA muscle coordination specific to defecation; and patient education to improve self-management of symptoms.^26,32–35 Because of the multifaceted nature of DD, administering these interventions at the optimal time and intensity during the course of physical therapy treatment requires advanced training and skill and thus is best provided by a physical therapist specialist in pelvic-floor dysfunction.

Figure 2.

Defecatory process.^107–112 The defecatory process begins with rectal distension eliciting a series of reflexes ending in the expulsion of stool. RAIR=rectoanal inhibitory reflex, IAS=internal anal sphincter, EAS=external anal sphincter, SR=sampling reflex, IAP=intra-abdominal pressure, CR=closing reflex, PR=puborectalis.

Normally, as stool distends the rectal wall, pressure receptors activate the rectoanal inhibitory reflex, resulting in internal anal sphincter relaxation and EAS contraction (Fig. 2).^107–112 The EAS remains active to prevent fecal incontinence, as the sampling reflex allows stool to enter the upper anus where stool consistency (liquid, solid, gas) is determined.¹¹³ As patient B has poor detection of stool entering the rectum, balloon catheter retraining is indicated to enhance rectal sensory awareness. The balloon catheter is inserted into the rectum and filled with air or water until the patient senses pressure. As her recognition of rectal pressure improves, the balloon is filled in smaller increments to further challenge her ability to sense lower rectal pressures.¹⁰⁸ This procedure has been found effective at reducing rectal hyposensitivity in 70% of patients.^3,114,115 As her rectal sensory awareness improves further, retraining of the defecatory process is initiated. This patient is advised to recognize and respond at the first urge to defecate (typically upon waking and following meals⁹) using proper toilet posture, sufficient intra-abdominal force, and timely coordination between the EAS and PR-LA at each phase of the defecation process.⁴⁶

During distinct phases of stool expulsion, the PR-LA and EAS act in parallel or independently to coordinate expulsion. If patient B's constipation also is attributed to a failure to relax the PR-LA and EAS during various phases of stool expulsion, internal rectal or vaginal palpation is recommended to train the process of PR-LA and EAS relaxation during bearing down to propel stool caudally.⁷⁴ If the patient is still unable to perform this skill, other forms of biofeedback can be used to promote motor learning.

The benefits of instrumented biofeedback training to promote coordinated relaxation of EAS and PR-LA during straining to defecate are well described in the literature.^116,117 Three controlled trials showed biofeedback therapy to be superior in the management of dyssynergic defecation compared with polyethylene glycol,¹¹⁸ sham feedback,¹¹⁹ and diazepam.¹¹⁷ Biofeedback training for short- and long-term management of dyssynergic defecation has been given a level 1, grade A recommendation.¹²⁰ Short-term management of levator ani syndrome (nonrelaxing muscle) with dyssynergic defecation using biofeedback has been given a level II, grade B recommendation.¹²⁰ However, to promote coordination between abdominal wall muscle activation and PR-LA and EAS relaxation required for stool expulsion, verbal training alone or verbal training supplemented by instrumented biofeedback is equally effective in promoting motor learning.⁴ Despite this evidence, there continues to be a dependence on instrumented biofeedback training to treat people with DD. As a result, other neuromuscular impairments contributing to dyssynergia may be ignored. This problem is perpetuated by a lack of awareness in the medical community regarding the availability of physical therapists with expertise in pelvic-floor dysfunction to treat people with DD.^3,121 Regardless of delivery method, augmented feedback should be reduced in frequency over time, allowing the patient to develop self-awareness of correct PR-LA and EAS contraction and relaxation.⁷⁶

If patient B is still unable to defecate following motor coordination training, myofascial restriction or trigger points in the PR-LA and EAS also may be contributing to DD. The medical community has historically managed DD by invasive procedures with varying associated risks, including injections (botulinum toxin or steroid with local anesthetic) and surgical myotomy.^30,122,123 Alternatively, myofascial release, a noninvasive, low-risk intervention is used to address myofascial impairments located between the umbilicus and thighs.¹²⁴ Evidence supporting use of this intervention for people with constipation is lacking. However, one multicenter randomized controlled trial of women with interstitial cystitis or painful bladder syndrome and PR-LA and EAS tenderness to palpation showed that 59% of the women assigned to the myofascial release intervention obtained moderate or marked improvement compared with 26% of those who received general massage.¹²⁵ If intravaginal or intrarectal myofascial release provided short-term improvement in volitional muscle relaxation, patient B will be instructed in self-administered myofascial release using a Food and Drug Administration–approved intrapelvic trigger point wand. Anderson et al¹²⁶ found no adverse events following self-management of trigger points using this type of device 2 to 4 times per week in people with chronic pelvic pain.

Finally, if patient B is still unable to expel stool, it may be due to ineffective rectoabdominal wall reflex activation. This reflex assists rectal peristaltic contractions in pushing stools toward the anus.¹⁰⁶ Weak or uncoordinated abdominal wall muscles or impaired diaphragm excursion may impede this reflex from generating sufficient intra-abdominal pressures.^127,128 The balloon catheter can be used to help the patient learn to generate these propulsive forces by instruction in diaphragmatic excursion^129,130 with coincident contraction of abdominal wall muscles, including the transversus abdominis,¹²⁸ external and internal oblique,¹³¹ and rectus abdominis muscles.^{35,105,106,128,132} While the patient attempts to expel the balloon, verbal cueing is provided to relax the PR-LA and EAS and to bear down with coordinated diaphragmatic excursion and abdominal wall activation. Gentle traction can be applied to the balloon by the physical therapist to assist the patient's expulsion efforts.¹¹⁴ This procedure may improve patient B's ability to learn and execute the mechanics of defecation. Although specialist physical therapists use balloon catheters to provide feedback for both sensory retraining and muscle coordination, the origin of and evidence for their use are only documented in the medical literature.^35,106

Summary

The purpose of this perspective article is to increase the knowledge base of physical therapists regarding functional constipation, including etiology, epidemiology, classification, and physical therapist management (including outside referral to other health professionals). Using the ICF model, we illustrated how patients with STC and DD may experience similar impact at the activity and participation levels, yet etiology and impairments underlying their conditions differ. Although physical therapist management for STC and DD can overlap, distinctly different interventions were presented through 2 patient examples. Through these examples, we acknowledged areas where evidence to support certain interventions is limited, indicating areas of needed research. However, it is our perspective that physical therapist management can be an effective first-line intervention for individuals with functional constipation. Key points from this perspective article are presented in  Appendix 5.

Appendix 1.

Pertinent Questions to Ask When Obtaining a History to Clarify Patients' Symptoms and Behaviors That May Affect Bowel Function^{3,15,20,21,26,32,35,44,48,–,51,94} and Red Flag Conditions for Constipation^48,52,53,79

Appendix 2.

Elements of the Physical Therapist Examination for Functional Constipation Disorders^a

Appendix 3.

Appropriate Physical Therapy Referral for Common Symptoms Present With Functional Constipation^a

Appendix 4.

Examination Findings and Prescribed Interventions for Patients A (Slow Transit Constipation Type) and B (Disorder Defecation Type)

Appendix 5.

Perspective on Adult Functional Constipation: Key Points to Consider^a

Author notes

Both authors provided concept/idea/project design and writing. Dr Borello-France provided project management and consultation (including review of manuscript before submission).

Dr George is an Orthopaedic Certified Specialist and a Women's Health Certified Specialist.