Patsy Catsos, MS, RDN, LD

Patsy Catsos, MS, RDN, LD

Nutrition Consultant, FODMAP Expert


IBS, FODMAP, GI Disorders, Gastrointestinal Health


Cornell University, Boston University



Patsy Catsos, MS, RDN, LD, is a former writer for Verywell Fit covering gastrointestinal health and irritable bowel syndrome. She is a registered dietitian nutritionist with a private practice in Portland, Maine. 

Patsy has been using the FODMAP approach with irritable bowel syndrome patients since 2008. After reading the early peer-reviewed literature about FODMAPs out of Australia’s Monash University Department of Gastroenterology, she set about developing a program to help her patients with IBS free themselves from the devastating symptoms of IBS. Keenly interested in digestive health and nutrition since her own diagnosis with ulcerative colitis 25 years earlier, she had never seen a dietary approach for managing gastrointestinal symptoms produce such fast, effective results. Her 2009 book IBS—Free at Last! introduced consumers and health care providers to the power of the FODMAP elimination diet. The latest edition of her book and program, now titled The IBS Elimination Diet and Cookbook, was published in 2017 by Harmony Books, an imprint of Penguin Random House. She is also the author of The IBS-Free FODMAP Toolkit for RDNs, a collection of reproducible patient handouts, forms, and nutrition care planning advice for healthcare professionals.

Patsy is a professional member of the Crohn’s and Colitis Foundation of America and the Academy of Nutrition and Dietetics. She is an active member and a past-president of the Maine Academy of Nutrition and Dietetics; she was honored as Maine's 2014 Outstanding Maine Dietitian of the Year.


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