John C. Byrn, MD


Colorectal Surgeon
Chief, Section of Colorectal Surgery
Clinical Assistant Professor of Surgery  - Gastrointestinal, Minimally-invasive and Bariatric Surgery

Contact Information

Primary Office: 4577 JCP
Iowa City, IA 52242
Primary Office Phone: 319-384-7359



BA, Chemistry, Hope College
MD, University of Illinois at Chicago College of Medicine

Residency, Department of Surgery, Mount Sinai School of Medicine
Chief Resident, Department of Surgery, Mount Sinai School of Medicine
Fellowship, Department of Colon and Rectal Surgery, Digestive Disease Institute , Cleveland Clinic Foundation

Licensure and Certifications

Iowa Medical License, Iowa Board of Medicine
Board Certified, Colon and Rectal Surgery, American Board of Colon and Rectal Surgery
Board Certified, General Surgery, American Board of Surgery

Selected Publications

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Bhama A, Charlton M, Schmitt M, Cromwell J, Byrn J.  Factors Associated with Conversion from Laparoscopic to Open Colectomy using the National Surgical Quality Improvement Program (NSQIP) Database.  Colorectal Disease.  2014 October 14. 

Wideroff M, Xing Y, Liao J, Byrn J.  Crohn’s Disease but not Diverticulitis is an Independent Risk Factor for Surgical Site Infections in Colectomy.  Journal of Gastrointestinal Surgery.  2014 October. 18(10):1817-1823.

Wertzberger B, Sherman S, Byrn J.  Differences in Short-Term Outcomes Among Ileal Pouch-Anal Anastomosis Patients Receiving Preoperative Radiation Versus Not: A NSQIP Analysis.  Diseases of the Colon and Rectum.  2014 October. 57(10):1188-1194.

Byrn J, Hrabe J, Charlton M.  An initial experience with 85 consecutive robotic assisted rectal dissections: Improved operating times and lower costs with experience.  Surgical Endoscopy.  2014 June 14. 

Sherman S, Hrabe J, Charlton M, Cromwell J, Byrn J.  Development of An Improved Risk Calculator for Complications in Proctectomy.  Journal of Gastrointestinal Surgery.  2014 May. 18(5):986-994.

Hrabe J, Sherman S, Charlton M, Cromwell J, Byrn J.  The Effect of BMI on Outcomes in Proctectomy.  Diseases of the Colon & Rectum.  2014 May. 57(5):608-615.

Hrabe J, Byrn J, Button A, Zamba G, Kapadia M, Mezhir J.  A Matched Case-Control Study of IBD-Associated Colorectal Cancer: IBD Portends Worse Outcome.  Journal of Surgical Oncology.  2014 February. 109:117-121.

Byrn J.  Technical considerations in laparoscopic total proctocolectomy.  Surgery Laparoscopy, Endoscopy & Percutaneous Techniques.  2012 June. 22(3):180-2.

Byrn J, Maun D, Gingold D, Baril D, Ozao J, Divino C.  Predictors of mortality after colectomy for fulminant Clostridium difficile colitis.  Archives of Surgery.  2008 February. 143(2):150-4.

Byrn J, Schlager A, Divino C, Weber K, Baril D, Aufses Jr. A.  The Management of 38 Anastomotic Leaks following 1,684 Intestinal Resections.  2006 March 30. 

Date Last Modified: 10/15/2014 - 12:57:45