Our Health Library information does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their health. Our providers may not see and/or treat all topics found herein. Crohn's disease is a long-term (chronic) inflammatory bowel disease (IBD). In Crohn's disease, parts of the digestive system get swollen and irritated and may have sores called ulcers. This can cause symptoms such as diarrhea, belly pain, and weight loss. Crohn's disease can affect any part of the digestive tract, from the mouth to the anus. Crohn's disease most often affects the part of the small intestine (ileum) that joins the large intestine. Crohn's disease can be in more than one area in the digestive tract at the same time. Doctors don't know what causes Crohn's disease. You may get it because your immune system has an abnormal response to normal bacteria in your intestine. Other kinds of bacteria and viruses may also play a role in causing the disease. Crohn's disease may run in families. Smoking puts you at a higher risk. The main symptoms of Crohn's disease are belly pain and diarrhea (sometimes with blood). Losing weight without trying is another common symptom. Some people may have only mild symptoms. Some may go for periods of time without symptoms (remission). A few people have ongoing moderate to severe symptoms. Your doctor will ask you about your symptoms and do a physical exam. You may have blood tests, a stool test, and X-rays. Imaging tests, such as a CT scan or an MRI, may be done. Tests that look inside the colon and take a sample (biopsy) may also be done. Your treatment will depend on your symptoms and how bad they are. Medicines are the most common treatment for Crohn's disease. Mild symptoms may be treated with over-the-counter medicines to stop diarrhea. You may also use prescription medicines to treat and prevent symptoms. Some people need other treatments, such as surgery. The main symptoms of Crohn's disease are belly pain and diarrhea (sometimes with blood). Losing weight without trying is another common symptom. Less common symptoms include mouth sores, bowel blockages, anal tears (fissures), and sores (ulcers) that form tunnels (fistulas) between organs. Infections, hormonal changes, smoking, medicines, and lifestyle changes can cause your symptoms to flare up. Your symptoms may be mild, moderate, or severe. Crohn's disease may cause sores, or ulcers, that form a tunnel through the intestine and into the nearby tissue. They are often around the anus and rectum. These tunnels, called fistulas, are a common problem with Crohn's disease. They may get infected. Crohn's disease can also cause anal fissures. These are narrow tears in the tissue from the muscles that control the anus (anal sphincters) up into the anal canal. In long-term Crohn's disease, scar tissue may form and cause blockages (bowel obstructions) or narrowed areas (strictures). These can prevent stool from passing through the intestines. Blockages in the intestines also may be caused by inflammation and swelling, which may improve with medicines. Sometimes blockages can only be treated with surgery. Sometimes symptoms of Crohn's disease affect other parts of the body. This can include the eyes, liver, blood, and bones. Call 911 anytime you think you may need emergency care. For example, call if: Contact a doctor now if you have been diagnosed with Crohn's disease and you have: If you have any of these symptoms and you have been diagnosed with Crohn's disease, your condition may have become much worse. Some of these symptoms, such as severe belly pain and bloating, also may be signs of toxic megacolon. This is a rare complication of Crohn's disease that requires emergency treatment. Without treatment, it can cause the colon to leak or rupture, which can be fatal. People who have Crohn's disease usually know their pattern of symptoms. Watch closely for changes in your health, and be sure to contact your doctor if: Your doctor will ask you about your symptoms and do a physical exam. You may also have blood tests or imaging tests to find out if you have Crohn's disease. Tests that may be done to diagnose or evaluate Crohn's disease include: Your treatment will depend on the type of symptoms you have and how bad they are. Medicines are the most common treatment for Crohn's disease. Mild symptoms may be treated with over-the-counter medicines to stop diarrhea. Prescription medicines can control or prevent inflammation in the intestines and help relieve symptoms. They also promote the healing of damaged tissues. People who have more severe, ongoing symptoms may need other treatments. These may include liquid feedings (supplemental nutrition) to let the intestines rest and heal or surgery to remove the damaged part of the intestine. Medicines usually are the treatment of choice for Crohn's disease. They can control or prevent inflammation in the intestines. They help to: They include: Research on new medicines and combinations of medicines is ongoing. Talk to your doctor about what medicines are best for you, based on the symptoms you have. Current as of: February 27, 2026 Author: WebMD Ignite Staff Current as of: February 27, 2026 Author: WebMD Ignite Staff Clinical Review Board This information does not replace the advice of a doctor. WebMD Ignite disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use and Privacy Policy. Learn how we develop our content. To learn more about WebMD Ignite, visit webmdignite.com. © 2024-2026 WebMD Ignite.Crohn's Disease
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All WebMD Ignite education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
All WebMD Ignite education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.
Our Health Library information does not replace the advice of a doctor. Please be advised that this information is made available to assist our patients to learn more about their health. Our providers may not see and/or treat all topics found herein. Current as of: February 27, 2026 Author: WebMD Ignite Staff Clinical Review BoardCrohn's Disease
All WebMD Ignite education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

