Considerations in case of suspected anastomotic leakage in the lower GI tract.

Colorectal anastomotic leakage (CAL) remains a feared complication after colorectal surgery and requires prompt detection and proper treatment. With the upswing of fast-track recovery programs in recent years this challenge has increased, as clinical features may only arise after discharge. Therefore, identification of the best diagnostic tools is of utmost importance, also since early treatment is associated with high success rates. Diagnostic tools range from general screening tools to invasive procedures to assess the severity of the leak. Laboratory tests, in particular the inflammation biomarkers C-reactive protein and procalcitonin, have a significant role in the detection of CAL after colorectal surgery. As these biomarkers are unspecific for CAL, additional imaging should be performed when blood levels are elevated. The golden standard for the detection of AL after colonic resections is a computed tomography (CT-scan). If tolerated, a contrast medium should be administered rectally to enhance diagnostic accuracy. When suspicion of CAL remains high despite negative previous tests, further endoscopy examination should be conducted. However, endoscopic examinations become more suitable for the early diagnostic work-up after rectal resections. This review aims to provide an overview of current diagnostics for the screening and assessment of the severity of CAL after colorectal surgery.