Disorders of the Colorectum

The most common colorectal disorders requiring surgery in the elderly are cancer, volvulus, diverticular disease, and vascular ectasias. Cancer is discussed in Ch. 113, and diverticular disease and vascular ectasias in Ch. 107. Ulcerative colitis is an uncommon but serious problem and is discussed in Ch. 107.

Volvulus

Volvulus arises from a twist of the colon on its mesentery sufficient to produce intestinal obstruction. An unusually long, mobile mesentery in the affected segment or a lack of fixation is needed for the twist to occur. Unless the obstruction is relieved, it progresses proximally and distally because of gas formation within the occluded segment. As a result, the mesenteric vasculature supplying the involved segment is also occluded, and gangrene and perforation can follow.

Volvulus is common in the elderly and is most prevalent in inactive women who have restricted mental capabilities and who live in nursing homes. The combination of an unusually large, long colon and inadequate bowel hygiene is a contributing factor.

Sigmoid volvulus: Volvulus occurs most commonly in the sigmoid. Obstipation, cramps, and marked abdominal distention are the usual complaints. Abdominal x-ray shows a large, distended colon. Distention may be limited to the sigmoid loop but occasionally extends above the liver. A barium enema shows the typical bird-beak deformity at the level of the twist.

Usually, a long rectal tube can be passed through a sigmoidoscope (or colonoscope) beyond the obstruction; this can produce explosive deflation. If deflation is incomplete or gangrene is noted, immediate laparotomy is necessary. The colonoscope is useful in determining if gangrene is present. If deflation occurs, resection of the involved colonic segment is performed electively during the same hospitalization, unless overriding reasons to defer surgery exist. If surgery is not performed, the probability of recurrence is very high.

Cecal volvulus: The cecum is another likely site for volvulus. It produces abdominal cramps, nausea, vomiting, distention, and obstipation. Abdominal x-ray shows a large gas bubble in the midabdomen or the left upper quadrant. Barium enema shows the typical bird-beak deformity in the ascending colon and no reflux into the ileum. Gangrene supervenes rapidly, so immediate surgery is essential. If no evidence of gangrene exists, the cecum can be anchored by a cecostomy tube after the twist has been reduced. The alternative for low-risk patients is immediate resection and reanastomosis. When gangrene and perforation with fecal contamination occur in a high-risk patient, resection and the formation of ileal and colonic fistulas are necessary. Intestinal continuity is reestablished later. If fecal contamination is slight or the cecum remains intact, a cecectomy with the ileum anastomosed to the ascending colon or a right colectomy is performed.