Ileal conduit to small intestine fistula following extensive abdominopelvic resection and radiation for metastatic colon cancer.

A woman in her mid-60s presented with decreased output from urostomy, which was an opening from the neobladder (ileal conduit). Presentation was preceded by a 6-month history of alternating faecaluria and increased colostomy output. Laboratory studies were notable for normal anion gap metabolic acidosis. Creatinine level of the colostomy output was 17.7 mg/dL, a finding indicative of the presence of urine in the sample. CT enterography and X-ray loopogram confirmed neobladder to small intestine fistula.Neobladder creation is commonly performed in patients with bladder cancer requiring resection. Fistulas between the neobladder and intestine are observed in fewer than 2.7% of cases. The patient's history of extensive abdominopelvic resection, colostomy creation and radiation likely contributed to fistula development. We highlight the need for a high index of suspicion for a fistula in a patient with a neobladder experiencing recurrent urinary tract infections or a high colostomy output concurrently with low neobladder output.