Professional Societies:
- American College of Surgeons
Fellowship 1988; Council Member, Metropolitan
Chapter, 1993-1995 - American Society of Colon and Rectal Surgeons
- Chicago Medical Society
- Chicago Society of Colon and Rectal Surgeons
Vice President, 1999-2000;
President, 2000-2001 - Chicago Society of Gastroenterology
- Chicago Surgical Society
- Collaborative Group of the Americas on Inherited Colorectal Cancer
- Crohn's and Colitis Foundation of America
Chairman CMAC, 1991-1994 Field Chairman 1994-1996 Board Member 1994-Present
- Eastern Cooperative Oncology Group (ECOG)
- Illinois State Medical Society
- Illinois Surgical Society
- James T. Priestley Surgical Society
Council Member, 1990-1992 - Royal Society of Medicine, Section of Colo-Proctology
- Society for Surgery of the Alimentary Tract
- Society of Surgical Oncology
- St. Mark's Association
- Western Surgical Association