Crohn's is a form of chronic inflammatory bowel disease that occurs in the deep layers of the intestinal wall and has periods of remission (time when you feel well) and relapse (when you feel ill). The most common area affected is the lower part of the small intestine just before it meets the colon, this is known as the ileum. Crohn's disease can infrequently affect any part of the upper gastrointestinal tract. Aphthous ulcers, which are similar to canker sores, are common. Ulcers can also occur in the esophagus, stomach and upper small intestine (duodenum).
The exact cause of Crohn's disease remains unknown. Previously, diet and stress were suspected, but now doctors know that these factors may aggravate but don't cause Crohn's disease. A number of factors, such as heredity and a malfunctioning immune system (autoimmune), likely play a role in its development.
Signs and symptoms of Crohn's disease can range from mild to severe. They usually develop gradually, but sometimes will come on suddenly, without warning. This is typically referred to as a “flare”. You may also have periods of time when you have no signs or symptoms (remission).
When the disease is active, signs and symptoms may include:
- Diarrhea. Intensified intestinal cramping also can contribute to loose stools.
- Fever and fatigue. This is likely due to presence of active inflammation or infection.
- Abdominal pain and cramping. Inflammation and ulceration can affect the normal movement of contents through your digestive tract and may lead to pain and cramping. You may experience anything from slight discomfort to severe pain, including nausea and vomiting.
- Blood in your stool.
- Mouth sores. You may have ulcers in your mouth similar to canker sores.
- Reduced appetite and weight loss. Abdominal pain and cramping and the inflammatory reaction in the wall of your bowel can affect both your appetite and your ability to digest and absorb food.
- Perianal disease. You might have pain or drainage near or around the anus due to inflammation from a tunnel into the skin (fistula).
People with severe Crohn's disease may also experience:
- Inflammation of skin, eyes and joints
- Inflammation of the liver or bile ducts
- Delayed growth or sexual development, in children
Your doctor will likely diagnose Crohn's disease only after ruling out other possible causes for your signs and symptoms. There is no one test to diagnose Crohn's disease.
Your doctor will likely use a combination of endoscopy with biopsies and radiological testing to help confirm a diagnosis of Crohn's disease. You may have one or more of the following tests and procedures:
- Tests for anemia or infection.
- Fecal occult blood test. You may need to provide a stool sample so that your doctor can test for hidden blood in your stool.
- Colonoscopy. This test allows your doctor to view your entire colon, as well as a portion of the ileum, using a thin, flexible, lighted tube with an attached camera. During the procedure, your doctor can also take small samples of tissue (biopsy) for laboratory analysis, which may help confirm a diagnosis. Clusters of inflammatory cells called granulomas, if present, help confirm the diagnosis of Crohn's.
- Flexible sigmoidoscopy. In this procedure, your doctor uses a slender, flexible, lighted tube to examine the sigmoid, the last section of your colon. Computerized tomography (CT scan). This test looks at the entire bowel as well as at tissues outside the bowel. CT enterography is a special CT scan that provides better images of the small bowel. This test has replaced barium X-rays in many medical centers.
- Magnetic resonance imaging (MRI). An MRI scanner uses a magnetic field and radio waves to create detailed images of organs and tissues. MRI is particularly useful for evaluating a fistula around the anal area (pelvic MRI) or the small intestine (MR enterography).
- Capsule endoscopy. For this test, you swallow a capsule that has a camera in it. The camera takes pictures, which are transmitted to a computer you wear on your belt. The images are then downloaded, displayed on a monitor and checked for signs of Crohn's disease by your doctor. The camera exits your body painlessly in your stool.
- Double-balloon endoscopy. For this test, a longer scope is used to look further into the small bowel where standard endoscopes don't reach. This technique is useful when capsule endoscopy shows abnormalities, but the diagnosis is still in question.
- Small bowel imaging. This test looks at the part of the small bowel that can't be seen by colonoscopy. After you drink a liquid containing barium, doctors take X-ray images of your small intestine to look for areas of narrowing which may suggest inflammation.
Treatment for Crohn's disease usually involves drug therapy or, in certain cases, surgery. There is currently no cure for the disease, and there is no one treatment that works for everyone.
The goal of medical treatment is to reduce the inflammation that triggers your signs and symptoms, and to improve long-term prognosis by limiting complications.
These are often the first step in the treatment of inflammatory bowel disease. They include oral 5-aminosalicylates and corticosteroids.
Immune system suppressors
These drugs also reduce inflammation, but they target your immune system, which is believed to be the cause of the inflammatory response. For some people, a combination of these drugs works better than one drug alone.
Antibiotics can reduce the amount of drainage and sometimes heal fistulas and abscesses in people with Crohn's disease. Some researchers also think antibiotics help reduce harmful intestinal bacteria that may play a role in activating the intestinal immune system, leading to inflammation.
In addition to controlling inflammation, some medications may help relieve your signs and symptoms, but always talk to your doctor before taking any over-the-counter medications. Depending on the severity of your Crohn's disease, your doctor may recommend one or more of the following:
- Pain relievers
- Iron supplements
- Vitamin B-12 shots
- Calcium and vitamin D supplements
Your doctor may use nutrition therapy short term and combine it with medications, such as immune system suppressors. Enteral (via feeding tube) and parenteral (given IV) nutrition are typically used to get people healthier prior to surgery or when other medications fail to control symptoms.
Your doctor may also recommend a low residue or low-fiber diet to reduce the risk of intestinal blockage if you have a narrowed bowel (stricture), as well as, to improve the regularity of your stools.
If diet and lifestyle changes, drug therapy or other treatments don't relieve your signs and symptoms, your doctor may recommend surgery. Up to one-half of individuals with Crohn's disease will require at least one surgery. However, surgery does not cure Crohn's disease.
During surgery, your surgeon removes a damaged portion of your digestive tract and then reconnects the healthy sections. Surgery may also be used to close fistulas and drain abscesses. The benefits of surgery for Crohn's disease are usually temporary. The disease often recurs, frequently near the reconnected tissue.