Open or laparoscopic colon resection is performed for a variety of conditions, the most common of which are benign or malignant neoplasms (tubular or villoglandular adenoma, adenocarcinoma, carcinoid, lymphoma); complications of diverticular disease (perforation with peritonitis or abscess, stricture, bleeding); extensive traumatic perforations; angiodysplasia or arteriovenous malformation with lower gastrointestinal bleeding; and inflammatory bowel disease (ulcerative colitis, segmental colonic Crohn's disease, toxic megacolon). Less common indications for resection include volvulus of the sigmoid colon or cecum; thrombotic, embolic, or low-flow infarction; and premalignant conditions (familial polyposis, Gardner's syndrome).

Hemicolectomy for malignant neoplasms involves excision of the area of the tumor, at least 10 cm of normal proximal colon or small bowel, and 5 cm of normal distal colon as well as excision of the regional lymphatics that accompany the major vessels in the mesentery. In contrast, segmental resection for complications of diverticular disease, Crohn's disease, colonic volvulus, or infarction involves only grossly diseased bowel without excision of the regional lymphatics. Subtotal abdominal colectomy with ileorectostomy is performed for patients with non-familial synchronous scattered benign or malignant neoplasms. It is also used in some patients with megacolon secondary to obstructing neoplasms of the sigmoid or rectosigmoid colon or of the upper rectum, and for patients with non-localized diverticular bleeding. For patients with severe medically refractory ulcerative colitis, familial polyposis, or Gardner's syndrome, a near-total abdominal colectomy is preferred. This involves preservation of a seromuscular short rectal cuff and the sphincter muscles to preserve anal continence and the creation of an ileal pouch–anal anastomosis.