A 60-year-old woman with recurrent urinary tract infection who had several operations for colorectal carcinoma underwent Tc-99m-DMSA renal scintigraphy which showed an unexpected accumulation of radiotracer in the colon. When symptoms were reviewed, we noticed that she was suffering from pneumaturia and fecaluria which raised the suspicion of enterovesical fistula. Rectal contrast-enhanced computer tomography of pelvis demonstrated enterovesical and enterovaginal fistulas. Colonic radioactivity was considered to be related to retrograde peristalsis of Tc-99m-DMSA from bladder activity via enterovesical fistula. In patients with pelvic surgeries and radiotherapy, radioactivity in the colon should raise the suspicion of enterovesical fistula.