Both Crohn's and ulcerative colitis (UC) are forms of Irritable Bowel Disease (IBD). (By the way, IBD is not the same as IBS, irritable bowel syndrome.) It can actually be very difficult to distinguish between Crohn's and UC, but one of the key differences involves the areas of your system that each attacks. Here are a few things that doctors tend to look for:
- Crohn's disease most commonly affects the last part of the small intestine and/or parts of the large intestine (also called the colon). However, Crohn's disease isn't limited to these areas and can attack any part of the digestive tract. UC tends to attack the large intestine and/or the rectum.
- Crohn's disease causes inflammation that extends much deeper into the layers of the intestinal wall than ulcerative colitis does.
- Crohn's disease generally tends to involve the entire bowel wall, whereas ulcerative colitis affects only the lining of the bowel.
- The best way for doctors to confirm their diagnosis is to do internal exams. This usually involves using a device called an endoscope and also by taking biopsies.