Factors influencing bowel function after low anterior resection and sigmoid colectomy

The aim of this study was to evaluate the subjective bowel function after low anterior resection and sigmoid colectomy and to clarify the clinicopathologic factors influencing postoperative bowel habits.

Eighty-six patients who underwent low anterior resection and sigmoid colectomy replied to the questionnaire which consisted of 8 categories of bowel symptoms. The patients were divided into 2 groups: good bowel function showing less than half of symptoms (< 4) and poor bowel function showing more than half of symptoms (> or = 4).

After low anterior resection, patients were often complicated with incomplete evacuation (75%), bowel movement at night (60%), defecation more than twice a day (46%), and soiling (27%). The mean number of defecation/day and frequency of patients with night stools was significantly higher after low anterior resection than sigmoid colectomy (2.81 vs. 2.18, P < 0.05; and 60% vs. 29%, P < 0.05). Poor bowel function after low anterior resection was frequent in patients with high ligation of the inferior mesenteric artery (82%, P < 0.05), injury to the pelvic autonomic nerve (82%, P < 0.05), and blood transfusion; while poor bowel function after sigmoid colectomy was frequent in patients with resected colon measuring 25 cm or more (81%, P < 0.05).

These results indicate that poor bowel function after low anterior resection is associated with high ligation of the inferior mesenteric artery and injury to the pelvic autonomic nerve; while poor bowel function after sigmoid colectomy correlates with length of the resected colon. Less aggressive surgery is needed to preserve good bowel function.