What is Crohn's disease?

Crohn’s Disease, also known as inflammatory bowl disease, is a chronic autoimmune disease, meaning the immune system attacks the body’s own cells. Although it can occur in any part of the gastrointestinal tract, the condition usually occurs in the ileum, which is the part of the gastrointestinal tract where the small and large intestines meet. Crohn’s Disease can cause inflammation, thickening of the intestinal wall and the formation of deep ulcers.

 

Crohn's disease is a chronic, or long lasting, disease that causes inflammation—irritation or swelling—in the gastrointestinal (GI) tract. Most commonly, Crohn's affects the small intestine and the beginning of the large intestine. However, the disease can affect any part of the GI tract, from the mouth to the anus.

 

Crohn's disease is a chronic inflammatory disease of the GI tract, called inflammatory bowel disease (IBD). Ulcerative colitis and microscopic colitis are the other common IBDs.  Crohn's disease most often begins gradually and can become worse over time. Most people have periods of remission—times when symptoms disappear—that can last for weeks or years.

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What is the gastrointestinal tract?

The GI tract is a series of hollow organs joined in a long, twisting tube from the mouth to the anus—a 1-inch-long opening through which stool leaves the body. The body digests food using the movement of muscles in the GI tract, along with the release of hormones and enzymes. Organs that make up the GI tract are the mouth, esophagus, stomach, small intestine, large intestine—which includes the appendix, cecum, colon, and rectum—and anus. The last part of the GI tract—called the lower GI tract—consists of the large intestine and anus. The intestines are sometimes called the bowel.

 

What causes Crohn's disease?

The exact cause of Crohn's disease is unknown. Researchers believe the following factors may play a role in causing Crohn's disease: Autoimmune reaction, Genes and/or Environment.

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Autoimmune reaction. Scientists believe one cause of Crohn's disease may be an autoimmune reaction—when a person's immune system attacks healthy cells in the body by mistake. Normally, the immune system protects the body from infection by identifying and destroying bacteria, viruses, and other potentially harmful substances. Researchers believe bacteria or viruses can mistakenly trigger the immune system to attack the inner lining of the intestines. This response causes inflammation, leading to symptoms.

 

Genes. Crohn's disease sometimes runs in families. Research has shown that people who have a parent or sibling with Crohn's disease may be more likely to develop the disease. Researchers continue to study the link between genes and Crohn's disease.

 

Environment. Some studies suggest that certain things (poorly-defined triggers) in the environment may increase the risk of someone already predisposed to developing Crohn's to develop the condition. However, these studies are very controversial, and overall chance of this actually occurring is extremely low.

 

Some people incorrectly believe that eating certain foods, stress, or emotional distress can cause Crohn's disease. Emotional distress and eating certain foods do not cause Crohn's disease. Sometimes the stress of living with Crohn's disease can make symptoms worse. Also, some people may find that certain foods can trigger or worsen their symptoms.

 

Who is more likely to develop Crohn's disease?

Crohn's disease can occur in people of any age. However, it is more likely to develop in people: Between the ages of 20 and 29, Who have a family member (most often a sibling or parent) with IBD and/or Who smoke cigarettes.​

 

What are the signs and symptoms of Crohn's disease?

The most common signs and symptoms of Crohn's disease are: diarrhea, abdominal cramping and pain and/or weight loss. Other general signs and symptoms include: feeling tired, nausea or loss of appetite, fever and/or anemia—a condition in which the body has fewer red blood cells than normal.

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Signs and symptoms of inflammation outside of the intestines include: joint pain or soreness, eye irritation and/or skin changes that involve red, tender bumps under the skin.

 

The symptoms a person experiences can vary depending on the severity of the inflammation and where it occurs.

 

How is Crohn's disease diagnosed?

A health care provider diagnoses Crohn's disease with the following: medical and family history, physical exam, lab tests, upper GI series, computerized tomography (CT) scan and/or intestinal endoscopy. The health care provider may perform a series of medical tests to rule out other bowel diseases, such as irritable bowel syndrome, ulcerative colitis, or celiac disease, that cause symptoms similar to those of Crohn's disease. Additional tests, like a colonoscopy or sigmoidoscopy, small bowel follow-through, and/or barium enemas may also be necessary.