Over a period of 30 years a total of 27 patients have been subjected to partial or complete colectomy and anastomosis for constipation. Patients fall into four groups: (i) functional constipation; (ii) adult megacolon; (iii) megasigmoid and (iv) persistent Hirschsprung's disease. The first two groups comprised 17 patients with resistant constipation, with or without megacolon or dolichocolon. Seven (41%) of these patients subsequently required operation for acute small-bowel obstruction due to adhesions. In two patients a permanent ileostomy was necessary for persistent rectal inertia after colectomy. The functional results in these first two groups were good. The third and fourth groups had similar presenting features; five had megasigmoid, and in these resection of the sigmoid colon gave good results. The remaining five patients with proven Hirschsprung's disease responded well to a pull-through resection (4) and to colectomy and anastomosis (1).