Anastomotic leakage is the most serious complication following colorectal resection. Recently, focus has been on possible effects of non-steroidal anti-inflammatory drugs (NSAIDs). Animal studies have found a correlation between treatment with NSAIDs and increased leakage rate, impaired anastomotic strength and reduced deposition of hydroxyproline. Retrospective human studies have reported increased leakage rates after postoperative diclofenac and celecoxib treatment. We recommend that diclofenac and celecoxib be omitted from analgesic regimens after colorectal surgery involving an anastomosis.