When the bowel meets the bladder: Optimal management of colorectal pathology with urological involvement.

Fistulae between the gastrointestinal and urinary systems are rare but becoming increasingly more common in current surgical practice. They are a heterogeneous group of pathological entities that are uncommon complications of both benign and malignant processes. As the incidence of complicated diverticular disease and colorectal malignancy increases, so too does the extent of fistulous connections between the gastrointestinal and urinary systems. These complex problems will be more common as a factor of an aging population with increased life expectancy. Diverticular disease is the most commonly encountered aetiology, accounting for up to 80% of cases, followed by colorectal malignancy in up to 20%. A high index of suspicion is required in order to make the diagnosis, with ever improving imaging techniques playing an important role in the diagnostic algorithm. Management strategies vary, with most surgeons now advocating for a single-stage approach to enterovesical fistulae, particularly in the elective setting. Concomitant bladder management techniques are also disputed. Traditionally, open techniques were the standard; however, increased experience and advances in surgical technology have contributed to refined and improved laparoscopic management. Unfortunately, due to the relative rarity of these entities, no randomised studies have been performed to ascertain the most appropriate management strategy. Rectourinary fistulae have dramatically increased in incidence with advances in the non-operative management of prostate cancer. With radiotherapy being a major contributing factor in the development of these complex fistulae, optimum surgical approach and exposure has changed accordingly to optimise their management. Conservative management in the form of diversion therapy is effective in temporising the situation and allowing for the diversion of faecal contents if there is associated soiling, macerated tissues or associated co-morbidities. One may plan for definitive surgical intervention at a later stage. Less contaminated cases with no fibrosis may proceed directly to definitive surgery if the appropriate expertise is available. An abdominal approach with direct repair and omentum interposition between the repaired tissues has been well described. In low lying fistulae, a transperineal approach with the patient in a prone-jack knife position provides optimum exposure and allows for the use of interposition muscle grafts. According to recent literature, it offers a high success rate in complex cases.