Ileum is the lowest part of the small intestine, the word ileum means twisted. When the small intestine is obstructed the ileum is twisted.
Crohn’s disease is an inflammatory bowel disease that usually affects the intestines, but may occur anywhere from the mouth to the end of the rectum.
While the exact cause of Crohn’s disease is unknown, the condition is linked to a problem with the body’s immune system response. With Crohn’s disease the immune system can’t tell the difference between normal body tissue and foreign substances. The result is an overactive immune response that leads to chronic inflammation of the gastrointestinal tract. Crohn’s disease may involve the small intestine, the large intestine, the rectum or the mouth.
Ulcerative colitis affects the colon and the rectum, causing inflammation and ulcers in the lining of the large intestine. The exact cause is unknown. Some think ulcerative colitis might be caused by the immune system overreacting to normal bacteria in the digestive tract.