Colon and Anorectum
The classic anatomic divisions of the colon are the cecum, colon proper, rectum, and anal canal. A surgical unit, the right colon, is composed of the cecum, ascending colon, and hepatic flexure. The surgical unit of the left colon consists of the distal transverse colon, splenic flexure, and descending and sigmoid colons. The layers of the wall of the large intestine are essentially similar to those of the wall of the small intestine. Evacuation is accomplished by the pelvic splanchnic nerves; continence is maintained by the pudendal and the pelvic splanchnic nerves.
A “decalogue of good colon surgery” introduces detailed step-by-step technique for performing cecopexy (colostomies), colon resection, (colectomies), abdominoperineal resections, and laparoscopic colectomies. Procedures of the surgical anal canal and perianal regions include repair of anal fissure, ligation of intersphincteric fistula tract (LIFT), hemorrhoidectomy (internal, external, thrombosed, band ligation), and excision of pilonidal cyst.