When is CT with rectal contrast indicated in patients suspected with anastomotic leak?

There is no clear guidance about the use of intraluminal rectal contrast combined with computerised tomography (CT) scan when assessing for anastomotic leak (AL) following colorectal resections. ALs most commonly manifest after post-operative day 5, presenting with fevers, abdominal pain, tachycardia and rising inflammatory markers. However, some patients with AL also present with subtle symptoms and failure to progress. CT with or without luminal contrast is the most commonly used investigation for diagnosis; however, there is no consensus on the best protocol. This case report highlights a need for having criteria, which include intra- and post-operative pointers when having a luminal contrast may aid diagnosis, in difficult cases. Studies show that routine contrast enema is not recommended, and furthermore, no gold standard investigation is available. This case report explores the need for a low threshold to use rectal contrast in CT in cases of prolonged ileus.