Functional colonic and anorectal disorders: Detecting and overcoming causes of constipation and fecal incontinence

Evaluation of constipation and fecal incontinence begins with comprehensive history taking, which may include overcoming a significant psychosocial barrier. Before functional anorectal diseases can be controlled, the fundamental cause must be determined and any underlying disorder corrected. In constipation, a colonic or anorectal motility disorder is often the cause; about half of refractory cases are the result of obstructive defecation. In fecal incontinence, dysfunction of several anatomic or physiologic mechanisms may be the cause. Anorectal manometry is useful in assessment in both disorders. Other helpful tests are colonic-transit measurement in constipation and electrophysiologic tests and defecography in fecal incontinence. Treatment of constipation often includes dietary measures and use of laxatives or prokinetic agents; fecal incontinence may respond to bulking or antidiarrheal agents. In both disorders, some patients have responded to the recently described technique of neuromuscular conditioning with biofeedback. In some cases, surgical repair must be considered.