Fecal incontinence is involuntary defecation.
(See also Evaluation of Anorectal Disorders.)
Fecal incontinence can result from injuries or diseases of the spinal cord, congenital abnormalities, accidental injuries to the rectum and anus, procidentia, diabetes, severe dementia, fecal impaction, extensive inflammatory processes, tumors, obstetric injuries, and operations involving division or dilation of the anal sphincters.
Physical examination should evaluate gross sphincter function and perianal sensation and rule out fecal impaction. Anal sphincter endoscopic ultrasonography, pelvic and perineal MRIs, pelvic floor electromyography, and anorectal manometry are also useful.
Treatment of fecal incontinence includes a bowel management program to develop a predictable pattern of defecation. The program includes intake of adequate fluid and sufficient dietary bulk. Sitting on a toilet or using another customary defecatory stimulant (eg, coffee) encourages defecation. A suppository (eg, glycerin, bisacodyl) or a phosphate enema may also be used. If a regular defecatory pattern does not develop, a low-residue diet and oral loperamide may reduce the frequency of defecation.
Simple perineal exercises, in which the patient repeatedly contracts the sphincters, perineal muscles, and buttocks, may strengthen these structures and contribute to continence, particularly in mild cases. Biofeedback (to train the patient to use the sphincters maximally and to better appreciate physiologic stimuli) should be considered before recommending surgery in well-motivated patients who can understand and follow instructions and who have an anal sphincter capable of recognizing the cue of rectal distention. About 70% of such patients respond to biofeedback.
A defect in the sphincter as assessed by endoscopic ultrasonography can be sutured directly. When there is insufficient residual sphincter for repair, particularly in patients < 50 yr of age, a gracilis muscle can be transposed. However, the positive results of these procedures typically do not last long. Some centers attach a pacemaker to the gracilis muscle, whereas others use an artificial sphincter; these or other experimental procedures are available in only a few centers in the US, as research protocols. Sacral nerve stimulation has shown promise in the treatment of fecal incontinence. Alternatively, a Thiersch wire or other material can be used to encircle the anus. When all else fails, a colostomy can be considered.