A series of patients with early or late obstruction of the small bowel after abdominoperineal resection is studied. Immediate intervention is recommended in patients with early obstruction; adhesions and defects of the pelvic floor are the most common etiologic factors in this group. Recurrent pelvic carcinoma with associated obstruction of the small bowel is the primary etiologic factor in patients with late obstruction. Bypass operation provides the best palliation. Simple adhesions continue to be a significant etiologic factor. No obstruction related to spaces created by colostomy was encountered.