Constipation and fecal incontinence are 2 forms of evacuatory dysfunction that cause significant morbidity across ages and populations. Both are end symptoms of a range of etiologies that are often linked. Diagnosis and treatment depend on a detailed examination and careful workup. Some etiologies are easily treated, whereas others require extensive therapy in a multidisciplinary setting.
Constipation is a broad term used by both patients and practitioners, with variable meaning. The Rome III definition of functional constipation requires 12 weeks of symptoms in the past 6 months, including at least 2 of the following symptoms: straining at defecation on at least 25% of defecations, lumpy or hard stools in at least 25% of defecations, sensation of incomplete evacuation for at least 25% of defecations, sensation of anorectal obstruction/blockage for at least 25% of defecations, manual maneuvers to facilitate at least 25% of defecations (eg, digital evacuation, support of the pelvic floor), and less than 3 defecations per week (Table 53-1).1
TABLE 53-1ROME III CRITERIA FOR FUNCTIONAL CONSTIPATIONa ||Download (.pdf) TABLE 53-1 ROME III CRITERIA FOR FUNCTIONAL CONSTIPATIONa
Must include 2 or more of the following:
Straining during at least 25% of defecations
Lumpy or hard stools in at least 25% of defecations
Sensation of incomplete evacuation for at least 25% of defecations
Sensation of anorectal obstruction/blockage for at least 25% of defecations
Manual maneuvers to facilitate at least 25% of defecations (eg, digital evacuation, support of the pelvic floor)
Fewer than 3 defecations per week.
|Loose stools are rarely present without the use of laxatives |
|Insufficient criteria for irritable bowel syndrome |
Pathophysiology and Etiology
Multiple conditions and medications can result in functional constipation. Colonic motility, rectal sensation, distention, and propulsion aided by pelvic floor relaxation must all work in concert for stool to develop normally and pass through the colon, rectum, and anus. Constipation can be classified into 3 broad subtypes: constipation-predominant irritable bowel syndrome (IBS-C), colonic transit disorder, and obstructed defecation syndrome (ODS). Differentiating between these 3 main etiologies requires a careful history and tailored evaluation.
IBS-C is a functional gastrointestinal disorder characterized by recurring symptoms of abdominal pain, bloating, and altered bowel habits. Irritable bowel syndrome (IBS) is suspected by recurrent abdominal pain or discomfort at least 3 days per month in the past 3 months associated with 2 or more of the following: improvement with defecation, onset associated with a change in frequency of stool, and onset associated with a change in form (appearance) of stool. IBS symptoms are not treated surgically.
Colonic transit disorder is a gastrointestinal dysmotility syndrome. Symptoms suggestive of slow transits include long intervals between bowel movements, ...