Explanation: Crohn's disease can develop anywhere in the digestive tract, including the esophagus, stomach, and even mouth. But it usually affects the lower end of small intestine, called the ileum, and the beginning of the large intestine, or colon. This makes it different from ulcerative colitis, which only affects the colon. Your symptoms depend on which part of your digestive tract is affected. Crohn's can also affect other parts of your body such as skin, eyes, joints, and liver.