1. Department of Urology, Division of Gastroenterology, University of California, Irvine, Orange, California.
2. Department of Surgery, Division of Gastroenterology, University of California, Irvine, Orange, California.
3. Department of Medicine, Division of Gastroenterology, University of California, Irvine, Orange, California.
4. Department of Urology, University Hospitals Case Medical Center, Cleveland, Ohio.