Ulcerative Colitis vs Crohn’s Disease: How These Bowel Diseases Differ Lisa Marie Conklin Replay Video Ulcerative colitis vs Crohn's disease: What's the difference? It's understandable if you confuse ulcerative colitis with Crohn's disease. Both of these chronic conditions are a type of inflammatory bowel disease that targets the digestive system with painful and burdensome symptoms. They both cause stomach pain and cramping, an urgent need to move the bowels, diarrhea, and fatigue. And they both have two phases of activity: flares (a recurrence of symptoms) and remission. On the surface, it can be hard to tell these inflammatory bowel diseases apart.