Constipation: Evaluation and Treatment of Colonic and Anorectal Motility Disorders
Section snippets
Epidemiology
Recent estimates based on householder surveys in North America suggest a prevalence rate of 15% to 20% for chronic constipation.1, 2, 3 However, other figures have been quoted and the discrepancies in the literature are largely due to how the problem has been defined or reported. The prevalence of constipation increases with age, especially in those over the age of 65 years.4, 5, 6 It also affects work-related productivity and leads to more absences from school.7 Constipation is associated with
Functional Subtypes
There is emerging consensus amongst experts that in the absence of alarm symptoms, such as weight loss, bleeding, recent change in bowel habit, and significant abdominal pain; or secondary causes, such as drugs, metabolic disorders, colorectal cancer, or local painful lesions, such as anal fissure,12 most patients with a complaint of constipation have a functional disorder affecting the colon or anorectum. At least three subtypes have been recognized, although overlap exists. Slow transit
Definition
Recent reviews and guidelines have addressed issues related to the definition of this common complaint.15, 19, 20, 21, 22, 23 Although infrequent defecation has generally been used to define constipation, such symptoms as excessive straining, passage of hard stools, or feeling of incomplete evacuation have only recently been recognized as equally important and perhaps more common.1 Thus, a definition that does not address the heterogeneity of symptoms that affect a patient with constipation is
Pathophysiology
The right colon performs several complex functions that include mixing, fermentation and salvage of the ileal effluent, secretion, and desiccation of the intraluminal contents to form stool. The left colon serves as a conduit for desiccation and more rapid transport of stool and the rectosigmoid region serves as a sensorimotor organ that facilitates the awareness, retention, and evacuation of stool when socially conducive. These functions are regulated by neurotransmitters, such as serotonin,
Clinical Features
Constipated patients present with a constellation of symptoms that include a feeling of incomplete evacuation; excessive straining; passage of hard, pellet-like stool; digital disimpaction or vaginal splinting; a lump-like sensation; or blockage in the anal region.9, 13 Additionally, they may report infrequent defecation, often less than three bowel movements per week; abdominal or anorectal discomfort; pain; or bloating.9 Patients may misrepresent their symptoms or may feel embarrassed to
Physical Examination
A thorough physical examination that includes a detailed neurological examination should be performed to exclude systemic illnesses that may cause constipation. The abdomen must be carefully examined for the presence of stool, particularly in the left or right lower quadrant. A normal physical examination is not uncommon but it is important to exclude a gastrointestinal mass. Anorectal inspection may reveal skin excoriation, skin tags, anal fissure, or hemorrhoids. Perineal sensation and the
Diagnostic Procedures
The first step in making a diagnosis of constipation is to exclude an underlying metabolic or pathologic disorder because constipation may be the first symptom of many organic conditions, such as colon cancer. A complete blood count, biochemical profile, serum calcium, glucose levels, and thyroid function tests are usually sufficient for screening purposes. If there is a high index of suspicion, serum protein electrophoresis, urine porphyrins, serum parathyroid hormone, and serum cortisol
Radiographic Studies
A plain radiograph of the abdomen may provide evidence for an excessive amount of stool in the colon. If colonoscopy has not been performed, a barium enema may be useful for excluding colonic pathology. Patients with constipation may have a redundant sigmoid colon, a megacolon, or megarectum. The presence of Hirschsprung's disease can also be detected by barium enema, although manometry and histology are required to confirm the diagnosis.
Management of Constipation
The first step in managing constipation is to exclude a secondary cause for constipation. This can be accomplished by performing the appropriate tests outlined above. Constipation may be caused by anatomical lesions of the colon or rectum, endocrine or metabolic disorders, neurologic diseases, or a variety of drugs.12 Constipation is a common and often overlooked adverse effect of many drugs. Some drugs have anticholinergic effects, others desiccate stool, and several others, including
Evidence-Based Summary for the Treatment of Constipation
A systematic review of the literature using an evidence-based approach for various treatment options is summarized in Table 2. For each specific content area, the supporting evidence was graded using a three-point graded scale.86 Level 1 evidence was derived from one or more randomized clinical trials. Level 2 evidence was supported by one or more well-designed cohort or case-control studies. Level 3 evidence was derived from expert opinion, based on clinical experience. Evidence was further
Summary
Constipation is a common polysymptomatic clinical disorder that affects up to 20% of the world's population. It leads to significant economic burden, loss of work-related productivity, and diminished quality of life. Studies over the past decade have led to an improved understanding of the underlying mechanisms, especially as they relate to colonic and anorectal function. Although many conditions, such as metabolic problems, fiber deficiency, anorectal problems, and drugs, can cause
References (118)
- et al.
An epidemiological survey of constipation in canada: definitions, rates, demographics, and predictors of health care seeking
Am J Gastroenterol
(2001) - et al.
Epidemiology of constipation (EPOC) study in the United States: relation of clinical subtypes to sociodemographic features
Am J Gastroenterol
(1999) - et al.
Gender, age, society, culture, and the patient's perspective in the functional gastrointestinal disorders
Gastroenterology
(2006) - et al.
Health-related quality of life, work productivity, and health care resource utilization of subjects with irritable bowel syndrome: baseline results from LOGIC (Longitudinal Outcomes Study of Gastrointestinal Symptoms in Canada), a naturalistic study
Clin Ther
(2006) Dyssynergic Defecation
Gastroenterol Clin North Am. Volume 30
(2001)- et al.
Mechanisms of Idiopathic Constipation: Outlet obstruction
Gastroenterology
(1978) - et al.
Physiology of Refractory Chronic Constipation
Am J Gastroenterol
(1999) - et al.
American Gastroenterological Association Medical Position Statement: guidelines on constipation
Gastroenterology
(2000) - et al.
Functional anorectal disorders
Gastroenterology
(2006) - et al.
Obstructive Defecation: A Failure of Rectoanal Coordination
Am J Gastroenterol
(1998)
Functional bowel disorders
Gastroenterology
Effects of Fat and Carbohydrate Meals on Colonic Motor Response
Gut
Characterization of a Hyperactive Segment at the Rectosigmoid Junction
Gastroenterology
Manometric Tests of Anorectal Function in Healthy Adults
Am J Gastroenterol
Decreased interstitial cell of cajal volume in patients with slow-transit constipation
Gastroenterology
Colonic Absorption in Idiopathic Constipation
Gastroenterology
Gastrointestinal transit: the effect of the menstrual cycle
Gastroenterology
Idiopathic chronic constipation is associated with decreased colonic vasoactive intestinal peptide
Gastroenterology
Serotonin and 5-hydroxyindoleacetic acid are increased in the sigmoid colon in severe idiopathic constipation
Gastroenterology
Role of progesterone signaling in the regulation of G-protein levels in female chronic constipation
Gastroenterology
Treatment of Animus in Intractable Constipation with Botulinum A Toxin
Lancet
Simplified Assessment of Segmental Colonic Transit
Gastroenterology
FECOM: A New Artificial Stool for Evaluating Defecation
Am J Gastroenterol
Rules of evidence and clinical recommendations on the use of antithrombotic agents
Chest
Effect of Dietary Fiber on Stool and Transit Times and its Role in the Causation of Disease
Lancet
Dietary Fiber and Personality Factors as Determinants of Stool Output
Gastroenterology
Cost-effective treatment of constipation in the elderly: a randomized double-blind comparison of sorbitol and lactulose
Am J Med
A randomized, placebo-controlled, multicenter study of the safety and efficacy of a new polyethylene glycol laxative
Am J Gastroenterol
A Longitudinal Survey of Self-reported Bowel Habits in the United States
Dig Dis Sci
Constipation in an elderly community: a study of prevalence and potential risk factors
Am J Gastroenterol
Physician visits in the United States for constipation: 1958 to 1986
Dig Dis Sci
Epidemiology of constipation in North America: a systematic review
Am J Gastroenterol
Direct medical costs of constipation in the United States
Manag Care Interface
Dyssynergic defecation: demographics, symptoms, stool patterns, and quality of life
J Clin Gastroenterol
Use of Health Care Resources and Cost of Care for Adults With Constipation
Clin Gastroenterol Hepatol
Constipation-Method of Conn's Current Therapy
Anismus in Chronic Constipation
Dig Dis Sci
Functional Disorders of the Anorectum
Gastroenterology International
Outlet Obstruction Constipation (Anismus) Managed by Biofeedback
Gut
Slow Transit Constipation
Gastroenterol Clin North Am
Functional Bowel Disorders and Functional Abdominal Pain
Gut
Functional Disorders of the Anus and Rectum
Functional disorders of the anus and rectum
Gut
Behavioural Modification of Colonic Function: Can Constipation be Learned?
Dig Dis Sci
Colonic Motor Response to Eating: A Manometric Investigation in Proximal and Distal Portion of the Viscus in Man
Am J Gastroenterol
Ambulatory 24-h Colonic Manometry in Healthy Humans
Am J Physiol Gastrointest Liver Physiol
Effects of Acute Graded Exercise on Human Colonic Motility
Am J Physiol
Twenty four hour manometric recordings of colonic motor activity in man
Gut
How useful are manometric tests of anorectal function in the management of defecation disorders?
Am J Gastroenterol
Colonic motor patterns in healthy humans: A 24 hour ambulatory study
Gastroenterology
Cited by (0)
This article appeared previously in the September 2007 issue of Gastroenterology Clinics of North America (36:3), with permission.
This work was supported in part by grant DK57100-0441 from the National Institutes of Health and in part by the Department of Internal Medicine, University of Iowa Carver College of Medicine.