Special considerations Abscess formation followin Special considerations: Abscess formation following intestinal surgery and anastomosis The development of an abscess following intestinal resection and anastomosis signifies infection of a haematoma or an anas - tomotic leak. Locules of gas or free contrast (Gastrografin) on CT support anastomotic leak. Pelvic abscess formation is not uncommon following excision of the rectum and formation of - a pelvic anastomosis.