In stapled anastomosis following anterior rectal resection, the anastomotic occlusive web rate is unknown and the management of this complication is not well defined. A 74-year-old man underwent a curative resection of a rectal cancer and, at the same time, a jejunal resection of an incidental stromal tumor. The colorectal anastomosis, performed according to the Knight-Griffen technique, and the hand-sewn end-to-end jejunal anastomosis were covered by a protective loop ileostomy. A number of features makes the case very unusual. The anastomotic occlusive web was made up of mucosal layer in the absence of a granulation reaction. Several factors contributed to the onset and misidentification of this complication. After the endoscopic approach had failed, the condition was successfully treated during an emergency operation for intestinal perforation.