Cecum: The first portion of the large bowel, which is situated in the lower-right quadrant of the abdomen. The cecum receives fecal material from the small bowel (ileum), which opens into it. The appendix is attached to the cecum. From Digestive Disorders Resources What Is Atypical Hemolytic Uremic Syndrome?How Ulcerative Colitis Affects Your BodyWhy Is Your Ulcerative Colitis Getting Worse? Featured Centers What Are the Best PsA Treatments for You?Understanding Biologics 10 Things People With Depression Wish You Knew Health Solutions From Our Sponsors