Ulcerative colitis is an inflammatory bowel disease (IBD). In this condition, the inner lining of your child’s large intestine (colon or bowel) and rectum gets inflamed. This inflammation often starts in the rectum and lower (sigmoid) intestine. Then it spreads to the whole colon.
This causes diarrhea or frequent emptying of the colon. As cells on the surface of the lining of the colon die and fall off, open sores (ulcers) form. This causes pus, mucus, and bleeding.
Crohn's disease occurs when there is redness and swelling (inflammation) and sores along your digestive tract. It is part of a group of diseases known as inflammatory bowel disease or IBD.
Crohn’s disease is a long-term, chronic illness that may come and go at different times in your life. In most cases, it affects the small intestine, most often the lower part called the ileum. In some cases it affects both the small and large intestines.
Sometimes the inflammation may be along your whole digestive tract. This includes your mouth, your food pipe (esophagus), your stomach, the first part of your small intestine or duodenum, your appendix, and your anus.