Crohn's Disease (CD)

Crohn's disease (CD) most commonly causes inflammation deep in the lining of the walls of the large intestine (colon) and/or the small intestine, but also can affect any part of the digestive tract from the mouth to the anus. Sometimes CD can affect other parts of the upper digestive tract with ulcers forming in the stomach, upper small intestine, or the esophagus. About one-third of cases of CD affect the small bowel, usually involving the ileum (the last portion of the small intestine that connects to the large intestine or colon). Nearly half of all cases involve both small and large bowel. About 20 percent of cases are in the colon alone. Lesions near the anus occur in about one-quarter to one-third of persons with CD but are rarely the only sole site of CD. Like UC, CD also is an illness that brings periods of remission and relapse.

The earliest most common symptoms are pain in the abdomen, especially the lower right side, tenderness, and often diarrhea. Constipation, weight loss, rectal bleeding, and low-grade fever also may occur. Bleeding may be bad enough to cause anemia or an unhealthy, low level of iron in the blood. Children with CD may have slowed growth and delayed sexual development in some cases.

The most common problem with CD is blockage of the intestine. Because swelling and scar tissue thicken the bowel wall, the intestine passage can become closed off. Fistulas, or abnormal connections between the intestine and other organs, can form from ulcers in the intestine, breaking through into other parts of the intestines or surrounding tissues of the bladder, vagina, or skin. They often form around the anus and rectum.

Nutrition problems are common with CD. Many people have deficiencies of proteins, calories, and vitamins. These can be caused by not eating enough, loss of protein within the intestine, or poor absorption. Osteoporosis also is a threat because of low Calcium and vitamin D intake through dairy products, poor absorption of nutrients in the body, or the use of corticosteroids (for treatment of CD or inflammation itself). Some persons with CD have problems with arthritis, their skin, inflammation in the eyes or mouth, kidney stones, gallstones, or other diseases of the liver. Some of these problems get better during treatment for disease in the digestive system, but some are treated separately.

In order to find out if you have CD, your doctor will examine you and may order blood tests to check for anemia (low iron levels) which could be a sign of bleeding in the intestine, or samples of a bowel movement to check for blood or germs. She also may do an upper gastrointestinal (GI) series to look at the small intestine. This is an x-ray that can show inflammation or other problems in the intestine. You also could have a barium enema, which is an x-ray of the colon, or the same screenings tests used to diagnose UC, flexible sigmoidoscopy or colonoscopy. These tests allow the doctor to view the lining of the colon. A CT scan may also be used to look for inflammation inside and outside the bowel.