The authors describe a 20-year-old man who was hospitalized for anemia and frequent attacks of right flank soreness. Right hydronephrosis was found incidentally on ultrasound. Renal scintigraphy revealed a urinary leak into the colon as a result of an unsuspected ureteroenteric fistula. The diagnosis of pyeloduodenal fistula was confirmed by retrograde pyelography.
From the *Division of Gastroenterology, Department of Internal Medicine, Cardinal Tien Hospital, Fu Jen Catholic University; and the †Department of Pathology, Tri-Service General Hospital, National Defense Medical Center, Taipei, Taiwan., R.O.C.
Received for publication May 21, 2003; revision accepted August 24, 2003.
Reprints: Ton-Ho Young, MD, Division of Gastroenterology, Department of Internal Medicine, Cardinal Tien Hospital, 362 Chung Cheng Road, Hsintien, Taipei Hsien, Taiwan 231, R.O.C. E-mail: firstname.lastname@example.org.