Crohn disease is a chronic disorder that affects the digestive system. Portions of the large intestine (the colon) and the small intestine (the ileum) are abnormally inflamed. The inflamed areas become thick and swollen, and ulcers can develop. Also known as colitis, enteritis, and ileitis, Crohn disease is a relatively common inflammatory bowel disease (IBD).
The disease often appears in the late teens or early twenties, though Crohn disease can develop at any age. Symptoms tend to flare up more than once throughout the course of a person’s life. Crohn disease is most commonly seen in North America and Western Europe, where as many as seven out of 100,000 people have the disease. Approximately one million Americans have Crohn disease.
Symptoms of Crohn disease include:
- Persistent diarrhea
- Abdominal pain
- Abdominal cramping
- Loss of appetite
- Weight loss
- Fever
Some people with Crohn disease also have chronic bleeding in the intestines, which can lead to a low red blood cell count (anemia). Crohn disease can also affect the joints, eyes, and skin. This disease can make it difficult to eat, and difficult for your body to get the nutrients it needs from food; this is why weight loss is a common symptom of Crohn disease.
Complications of Crohn disease include:
- Intestinal blockages caused by swelling in the intestines
- Intestinal blockages caused by scar tissue buildup in the intestines
- Fistulae — abnormal connections between intestines and other tissue, caused when ulcers break through the intestinal walls. Fistulae may connect different parts of the intestines, or may connect the intestines to other organs.
Both genetics and environment play a part in your risk of developing Crohn disease. Cigarette smoking is thought to increase a person’s risk of developing Crohn disease, and may increase or worsen a patient’s flare ups. The disease does tend to cluster in families; scientists are still identifying specific genes involved in passing on the disease.