GREG S. COHEN, MD

Gastroenterology

HOURS

Mon - Fri: 8am - 4pm
Sat and Sun: Closed

ABOUT DR. COHEN

Dr. Cohen practices General Gastroenterology with additional special focuses on Crohn's Disease, Ulcerative Colitis, and non surgical treatment of hemorrhoids. Dr. Cohen is originally from Potomac, Maryland. He completed his undergraduate work at Cornell University and medical school at the University of Maryland. Dr. Cohen moved to Chicago in 1998 where he completed his residency at Northwestern followed by a 4 year combined clinical and research GI fellowship under an NIH training grant at the University of Chicago. He has been in practice at Northwestern since 2005.

Dr. Cohen is board certified in Gastroenterology and is a Clinical Associate Professor of Medicine at Northwestern University. He is a fellow of both the American College of Gastroenterology and the American Gastroenterological Association. He is actively involved in teaching medical students as well as GI fellows, and has received multiple teaching awards from the Northwestern University Feinberg School of Medicine. He has published multiple papers and also serves as a peer reviewer.

Dr. Cohen's practice philosophy is simple: he takes care of his patients the way he would want any doctor to take care of him. Appointments are as long as they need to be. Phone calls and electronic messages to the doctor are always returned by the doctor himself, and usually within a few hours. Dr. Cohen is part of the private practice community at Northwestern Memorial Hospital.

To find other Northwestern private practice physicians, click this link.

Dr. Cohen is married with three children and one dog. He spends his free time with his family, building model rockets with his kids, skiing in the winter, and volunteering as camp doctor at his kids' summer camps in the North Woods of Wisconsin.

Click here to re ad an interview of Dr. Cohen in VoyageChicago.

Areas of Interest:

Celiac Disease, Colon Cancer Screening, Constipation, Crohn's Disease, Diarrhea, Familial Colon Cancer Syndromes, Hemorrhoid Treatment, Inflammatory Bowel Disease, Peptic Ulcer Disease, Rectal Bleeding, Swallowing Disorders, Ulcerative Colitis

Lay press references:

Questions and answers about IBD

Coffee and the GI tract

Runner's diarrhea

Publications:

Cohen GS, Kim KYA: “Fentanyl may not be necessary for adequate endoscopic moderate sedation.” World Journal of Gastrointestinal Endoscopy. 2025;17(5): Article ID 105031, 6 pages. https://www.wjgnet.com/1948-5190/full/v17/i5/105031.htm Than J, Cohen G: "Colovesical Fistula: An Uncommon Cause of Hematuria and Rectal Bleeding." Case Reports in Gastrointestinal Medicine. 2022; Article ID 1419250, 3 pages. https://doi.org/10.1155/2022/1419250 PMid:36388088 PMCid:PMC9646317 Cohen G, Shanahan C: "Benign Solitary Cecal Ulcer Syndrome." American Journal of Gastroenterology. 2020;115(3):317. https://doi.org/10.14309/ajg.0000000000000347 PMid:31397678 Cohen G: "Melanosis Coli." Clinical Gastroenterology and Hepatology. 2020;18(7):e71. https://doi.org/10.1016/j.cgh.2019.03.032 PMid:30928452 Schenck R, Cohen G, Pezhouh M: "Microscopic colitis: A rare cause of pseudomembranes." Clinical Gastroenterology and Hepatology. 2019;17(9):e101. https://doi.org/10.1016/j.cgh.2018.06.041 PMid:29981436 Cohen G, Schenck R: "Cryptosporidium pouchitis." Clinical Gastroenterology and Hepatology. 2017 Jul; 15(7): A27-A28. https://doi.org/10.1016/j.cgh.2017.02.010 PMid:28223201 Cohen G, Prasad M: "Campylobacter pouchitis mimicking the appearance of Crohn's Disease." Case Reports in Gastrointestinal Medicine. 2016, Article ID 5254914, 3 pages, 2016. https://doi.org/10.1155/2016/5254914 PMid:27555972 PMCid:PMC4983316 Lemmer A, Kia L, Cohen G: "A rare esophageal complication following autologous stem cell transplantation." Gastroenterology. 2015;148(4):717-718. https://doi.org/10.1053/j.gastro.2014.12.041 PMid:25721449 Cohen G, Prasad M: "To Band or Not to Band…" Gastroenterology. 2015;148(2):300-301. https://doi.org/10.1053/j.gastro.2014.10.054 PMid:25527970 Cohen G: "An Unusual Cause of Hematochezia in an Elderly Man." Gastroenterology. 2014;147(5):e6-e7. https://doi.org/10.1053/j.gastro.2014.05.040 PMid:25263300 Pekow J, Dougherty U, Huang Y, Gometz E, Nathanson J, Cohen G, Levy S, Kocherginsky M, Venu N, Westerhoff M, Hart J, Noffsinger AE, Hanauer SB, Hurst RD, Fichera A, Joseph LJ, Liu Q, Bissonnette M: "Gene Signature Distinguishes Patients with Chronic Ulcerative Colitis Harboring Remote Neoplastic Lesions." Inflammatory Bowel Diseases. 2013;19(3):461-70. https://doi.org/10.1097/MIB.0b013e3182802bac PMid:23388545 PMCid:PMC3836269 Roth MP, Cohen G: "A quarter causing intermittent gastric outlet obstruction." Gastrointestinal Endoscopy. 2012;75(1):189-190. https://doi.org/10.1016/j.gie.2011.10.027 PMid:22196819 Lin CF, Cohen G: "Endoscopic repair of colonic perforation following polypectomy." American Journal of Gastroenterology. 2009;104(11):2869-70. https://doi.org/10.1038/ajg.2009.423 PMid:19888259 Khare S, Mustafi R, Cerda S, Yuan W, Jagadeeswaran S, Dougherty U, Tretiakova M, Samarel A, Cohen G, Wang J, Moore C, Wali R, Holgren C, Joseph L, Fichera A, Chun Li Y, Bissonnette M: "Ursodeoxycholic acid suppresses Cox-2 expression in colon cancer cells: roles of Ras, p38, and CCAAT/Enhancer-Binding Protein." Nutrition and Cancer. 2008;60(3):389-400. https://doi.org/10.1080/01635580701883003 PMid:18444174 Fichera A, Little N, Jagadeeswaran S, Dougherty U, Sehdev A, Mustafi R, Cerda S, Yuan W, Khare S, Tretiakova M, Gong C, Tallerico M, Cohen G, Joseph L, Hart J, Turner JR, Bissonnette M: "Epidermal growth factor receptor signaling is required for microadenoma formation in the mouse azoxymethane model of colonic carcinogenesis." Cancer Research. 2007;67(2):827-35. https://doi.org/10.1158/0008-5472.CAN-05-3343 PMid:17234795 PMCid:PMC2705749 Cohen G, Mustafi R, Chumsangsri A, Little N, Nathanson J, Cerda S, Jagadeeswaran S, Dougherty U, Joseph L, Hart J, Yerian L, Tretiakova M, Yuan W, Obara P, Khare S, Sinicrope F, Fichera A, Boss G, Carroll R, Bissonnette M: "Epidermal Growth Factor Receptor Signaling is Up-Regulated in Human Colonic Aberrant Crypt Foci." Cancer Research. 2006;66(11):5656-64. https://doi.org/10.1158/0008-5472.CAN-05-0308 PMid:16740703 Cerda SR, Mustafi R, Little H, Cohen G, Khare S, Moore C, Majumder P, Bissonnette M: "Protein kinase C delta inhibits Caco-2 cell proliferation by selective changes in cell cycle and cell death regulators." Oncogene. 2006;25:3123-38. https://doi.org/10.1038/sj.onc.1209360 PMid:16434969 Khare S, Cerda S, Wali RK, von Lintig FC, Tretiakova M, Joseph L, Stoiber D, Cohen G, Nimmagadda K, Hart J, Sitrin MD, Boss GR, Bissonnette M: "Ursodeoxycholic Acid Inhibits Ras Mutations, Wild Type Ras Activation and Cyclooxygenase-2 Expression in Colon Cancer." Cancer Research. 2003;63(13):3517-3523. https://doi.org/10.1016/S0016-5085(03)83066-4 PMid: 12839936 Wali R, Khare S, Tretiakova M, Cohen G, Nguyen L, Hart J, Wang J, Wen M, Ramaswamy A, Joseph L, Sitrin M, Brasitus T, Bissonnette M: "Ursodeoxycholic Acid and F6-D3 Inhibit Aberrant Crypt Proliferation in the Rat Azoxymethane Model of Colon Cancer: Roles of Cyclin D1 and E-Cadherin." Cancer Epidemiology, Biomarkers & Prevention. 2002;11(12):1653-1662. PMid: 12496057