Severe chronic constipation can dramatically impact an individual's quality of life and can lead to serious medical problems if inadequately addressed. Although rare, severe chronic constipation has been associated with several potentially serious complications. The most common of these is fecal impaction, which is a particular risk among elderly adults and even more so among those residing in long-term care facilities. Chronic constipation sufferers are also at risk of developing a sigmoid volvulus (a "twist" in the colon) or a stercoral ulcer, both of which can result in colonic perforation.
When managing a patient for chronic constipation that does not respond to conventional treatments it is important to follow the following steps: Obtain a detailed history to determine what symptoms are not being addressed by current treatments, ensure the patient has had adequate trials of any medications taken, consider combining treatments, and evaluate patients for pelvic floor dysfunction (consider anorectal biofeedback if pelvic floor dyssynergia is present). Consider surgery only after all other treatments have failed and patients have been adequately evaluated to rule out diffuse dysmotility syndromes and psychological comorbidities.
Increasing fluids and dietary fiber and initiating an exercise program are often recommended as the first line therapy in patients with no known secondary causes of chronic constipation. While these measures are reasonable, studies evaluating the effects of these measures are inconclusive. In addition, many patients with chronic constipation will have attempted some versions of these treatments prior to coming to their clinician for help. Pharmacological options include bulking agents, stool softeners, stimulant laxatives and osmotic laxatives. A reasonable pharmacological approach for a patient with chronic constipation is to start with a bulk forming agent such as psyllium or bran followed by a stool softener or osmotic agent, such as lactulose or polyethylene glycol. If necessary, a stimulant laxative such as bisacodyl or senna could be used. Finally, the chloride channel activator lubiprostone could be tried in patients with persistent symptoms. These therapies appear to be safe for long-term use but patients should limit their use whenever possible and should periodically reduce or discontinue them to determine if long-term use is necessary.
Anorectal biofeedback is most effective in patients with pelvic floor dyssynergia or outlet obstruction. Surgery is rarely used as a therapy for chronic constipation. Patients most likely to benefit from surgery are those with persistent and intractable slow transit constipation after all other treatment options have been exhausted.
Anorectal manometry and defecography are the two most common tests used to assess for pelvic floor dysfunction or dyssynergic defecation. Anorectal manometry assesses pressures in the anal canal, at rest and during simulated defecation. Paradoxical contraction during simulated defecation or delay in balloon expulsion are findings that are suggestive of pelvic floor dysfunction. Defecography assesses the rectal anatomy at rest and during simulated defecation while sitting on a bedside commode in the fluoroscopy suite. Anatomical abnormalities of the rectosigmoid region that could contribute to constipation, such as a rectocele or sigmoidocele or intussusceptions, can be excluded.
In anorectal biofeedback patients are taught to retrain their anal sphincter during simulated defecation. Typically this procedure is done with a probe in the anal canal that can show the patient appropriate ways to relax their anal sphincter. Typically this will involve several different sessions and is most often conducted by a trained physical therapist. Studies performed to date have shown that anorectal biofeedback for patients with pelvic floor dysfunction can be quite effective in improving the symptoms associated with chronic constipation.
Constipation is a common condition that frequently impacts patients' quality of life and occasionally can be associated with significant complications. Pharmacological treatment options include increasing dietary fiber, stool softeners, osmotic and stimulant laxatives and a chloride channel opener, lubiprostone. Pelvic floor dyssynergia can be diagnosed with anorectal manometry and, when present, can be effectively treated with anorectal biofeedback. Surgical intervention is rarely necessary and should be limited to patients with severe refractory slow transit constipation in whom all other treatments have failed.
Anthony Lembo, MD
Associate Professor of Medicine
Department of Medicine
Division of Gastroenterology
Beth Israel Deaconess Medical Center
Harvard Medical School