Rectal Prolapse and Procidentia

Protrusion of part of the rectum through the anus.

Mucosal prolapse involves only the mucosal layer of the rectum. Complete prolapse involves all layers. In procidentia, the most severe form, several inches of rectum may pass through the anus.

Prolapse is common among elderly persons, affecting women more than men. The underlying defect is a long, lax sigmoidorectal mesentery that cannot keep the rectum in position.

Symptoms, Signs, and Diagnosis

The main symptom is protrusion of mucous membrane or the rectum, felt as an anal mass by the patient. Initially, manual reduction is possible, but later, protrusion occurs when the patient stands, causing pain and discharge of mucus and blood from the inflamed mucosa.

During physical examination, the degree of prolapse can be determined by inspecting and palpating the protrusion when the patient is squatting and straining or immediately after the patient has had a bowel movement. In complete prolapse, mucosal folds are circumferential and concentric. When prolapse is subtle, anal manometry and defecography may help in making the diagnosis.

Treatment

Conservative therapy (instruction to avoid straining at stool, lifting, and excessive standing; when necessary, manual reduction) provides temporary relief. However, early surgical repair is necessary, because continued dilation of the anal sphincters leads to fecal incontinence. The weakened muscular ring often remains incompetent despite later attempts at repair. For mucosal prolapse, redundant tissue is excised. For complete prolapse, conservative therapy may be used, but surgery should not be delayed.

Surgery usually involves transabdominal resection of redundant colon and rectum, coloanal anastomosis, or both. However, surgeons disagree about which specific procedure is best. Complications include intestinal obstruction if the loop is tied too tightly and recurrence if the loop breaks.

Postoperative fecal incontinence is common, particularly among patients with preoperative incontinence. Many surgeons prefer to surgically tighten the sphincter in such patients.