An Unusual Presentation of Diverticular Colovesical Fistula: Acute Renal Failure With Bilateral Emphysematous Pyelonephritis.

Colovesical fistula (CVF) is an abnormal connection between the urinary system and the bowel. It is a known complication of acute diverticulitis. Common symptoms include pneumaturia, fecaluria, and abdominal pain, amongst others. In this case, we report a rare case of acute renal failure due to a relatively asymptomatic colovesical fistula causing left-sided emphysematous pyelonephritis complicated by renal abscess. After appropriate surgical treatment and antibiotic therapy, the CVF, pyelonephritis, and abscess resolved. Unfortunately, renal function did not return to baseline, likely due to injury and poor functioning of the left kidney. Urology is considering radical nephrectomy to prevent recurrent of future infection. This case highlights a previously unknown and severe patient presentation of CVF and signifies the importance of maintaining a high index of suspicion of a fistula when a patient presents with recurrent urinary tract infections, acute renal failure, and colon pathology.