Some common intestinal diseases are colitis, irritable bowel syndrome (IBS), constipation, peptic ulcers, colon polyps or cancer, diverticular disease and intestinal obstruction. There are different forms of colitis, including infectious and ulcerative colitis, states Cleveland Clinic. Crohn's disease is also another form of colitis, in which there is bowel inflammation.
Many gastrointestinal disorders, such as an intestinal obstruction, a peptic ulcer or cancer, involve the small intestine, notes MedlinePlus. Peptic ulcers, which are lesions, can develop in a part of the small intestine called the duodenum. An intestinal obstruction happens when either food or stool cannot move through the intestines properly.
Similarly, colorectal cancer and polyps can also affect the colon, which is the large intestine, states Cleveland Clinic. Another issue that can develop in the intestines is diverticular disease, which is the formation of small pouches along the colon wall.