Inclusion Criteria:  Patients who underwent colon or colorectal anastomosis for neoplasia, diverticulitis, mesenterial ischemia, iatrogenic or traumatic perforation, or inflammatory bowel disease  Exclusion Criteria:  age < 18 recurrent colorectal cancer peritoneal carcinomatosis or unresectable metastatic disease at time of bowel resection informed consent not obtainable follow-up < 6 weeks after surgery no reversal of and ostomy