The cause of Crohn's disease is still not known. Heredity may have something to do with the disease's occurrence.
Food allergies may play a part in the development of the disease. Viral or bacterial infections may also be involved as well as autoimmune disorders (in which the body attacks its own cells, mistaking them to be invading agents).
People with Crohn's disease tend to have abnormalities of the immune system, but doctors do not know whether these abnormalities are a cause or result of the disease. Crohn's disease is not caused by emotional distress.
Symptoms include chronic diarrhea, pain in the in the middle and lower abdomen, headaches, fever, rectal bleeding or blood in the stool, anal cracking, and loss of weight, appetite and energy. Secondary symptoms may include mouth and anal sores and chronic bleeding that may result in anemia.
How Is It Diagnosed?
A thorough physical exam and a series of tests may be required to diagnose Crohn's disease.
Blood tests may be done to check for anemia, which could indicate bleeding in the intestines. Blood tests may also uncover a high white blood cell count, which is a sign of inflammation somewhere in the body. By testing a stool sample, the doctor can tell if there is bleeding or infection in the intestines.
The doctor may do an upper gastrointestinal (GI) series to look at the small intestine. For this test, the patient drinks barium, a chalky solution that coats the lining of the small intestine, before x-rays are taken. The barium shows up white on x-ray film, revealing inflammation or other abnormalities in the intestine.
The doctor may also do a colonoscopy. For this test, the doctor inserts an endoscope--a long, flexible, lighted tube linked to a computer and TV monitor--into the anus to see the inside of the large intestine. The doctor will be able to see any inflammation or bleeding. During the exam, the doctor may do a biopsy, which involves taking a sample of tissue from the lining of the intestine to view with a microscope.
If these tests show Crohn's disease, more x-rays of both the upper and lower digestive tract may be necessary to see how much is affected by the disease.
The most common complication is blockage of the intestine. Blockage occurs because the disease tends to thicken the intestinal wall with swelling and scar tissue, narrowing the passage. Crohn's disease may also cause sores, or ulcers, that tunnel through the affected area into surrounding tissues such as the bladder, vagina, or skin. The areas around the anus and rectum are often involved. The tunnels, called fistulas, are a common complication and often become infected. Sometimes fistulas can be treated with medicine, but in some cases they may require surgery.
Nutritional complications are common in Crohn's disease. Deficiencies of proteins, calories, and vitamins are well documented in Crohn's disease. These deficiencies may be caused by inadequate dietary intake, intestinal loss of protein, or poor absorption (malabsorption).
Other complications associated with Crohn's disease include arthritis, skin problems, inflammation in the eyes or mouth, kidney stones, gallstones, or other diseases of the liver and biliary system. Some of these problems resolve during treatment for disease in the digestive system, but some must be treated separately.