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INTRODUCTION — Crohn disease is a condition that affects the digestive tract. The cause of Crohn disease is unknown. The most common symptoms of Crohn disease include diarrhea, abdominal pain, weight loss, and fever. Some people with Crohn disease also have problems outside of the digestive tract, including a skin rash, joint pain, eye redness, and, less commonly, liver problems.
There is no cure for Crohn disease, but there are medicines that can help to keep the disease under control. If medicine does not control symptoms, surgery might be an option to remove the diseased part of the intestines.
This article discusses the symptoms and treatment of Crohn disease. More detailed information about Crohn disease, written for healthcare providers, is available by subscription. (See 'Professional level information' below.)
WHAT IS CROHN DISEASE? — Crohn disease is a condition that involves the body's immune system, which normally fights infection but attacks healthy tissue instead. The cause of Crohn disease is not known. Having family members with Crohn disease probably increases the risk of developing the condition. When a person with this inherited risk is exposed to a trigger (an illness or something in the environment), the immune system is activated.
In Crohn disease, your immune system recognizes the lining of your digestive tract as foreign and attacks it, causing inflammation. This inflammation causes the lining of your digestive tract to develop ulcers. Crohn disease usually affects the last part of the small intestine (called the "ileum") and some of the large intestine (colon) but it can affect the entire digestive tract, from the mouth to the anus (figure 1).
Crohn disease, like ulcerative colitis, is a type of inflammatory bowel disease. Inflammatory bowel disease should not be confused with irritable bowel syndrome. (See "Patient education: Ulcerative colitis (Beyond the Basics)" and "Patient education: Irritable bowel syndrome (Beyond the Basics)".)
There are several types of Crohn disease: inflammatory, where there is inflammation in the affected portion, fibrostenotic, where the inflammation causes scar tissue and narrowing of the bowel so that blockages occur, and penetrating (fistulizing), where the inflammation burrows through all layers of the bowel and causes a track on the outside of the gastrointestinal tract to another part of the body. Most often fistulas occur around the anal canal, to another portion of the bowel, or to the abdominal wall.
Will I get better? — Crohn disease typically follows a repeating cycle of intermittent flares (when the condition worsens and symptoms are present) followed by periods of remission (when inflammation is controlled and symptoms are absent).
The pattern can be variable, with flares often lasting weeks to months and involving symptoms such as mild diarrhea and cramping. Less commonly, there can be severe and disabling symptoms (such as severe abdominal pain and a blockage in the bowels). While 10 to 20 percent of people experience long-term disease remission after the initial flare, most people will continue to have disease flares. For anyone with Crohn disease, ongoing treatment increases the chance of entering and staying in remission.
CROHN DISEASE SYMPTOMS — The most common symptoms of Crohn disease involve the digestive tract and include:
●Unintentional weight loss
Some people get other symptoms and related disorders as well, including:
●Mouth sores – Mouth sores (called "aphthous stomatitis") can develop during flares of Crohn disease. They are usually found between the gums and lower lip, or along the sides or underside of the tongue (picture 1). Mouth sores are often painful. The medicines used to treat the digestive tract usually help to treat mouth sores as well.
●Arthritis – Arthritis or joint inflammation can occur in people with Crohn disease. It usually affects the larger joints, and is most active when the bowel symptoms are active.
●Eye inflammation – Inflammation of the eyes (called uveitis or scleritis) occurs in up to 5 percent of people with Crohn disease. These problems can affect one or both eyes. Symptoms of uveitis include "floaters" in the vision, eye pain, blurred vision, and sensitivity to light. Scleritis can cause burning or itching of the affected eye. Treatment usually includes eye drops.
●Anal problems – Crohn disease can cause problems in the area around the anus. The most common problems include fissures (tears), ulcers, fistulas (a tunnel between the intestine and other organs), infected areas of skin, and stenosis (narrowing of the anus). These problems may occur alone or in combination.
Anal problems sometimes heal on their own without treatment. In other cases, treatment with medicines or surgery will be required. Soaking your bottom in warm water a few times a day and gently cleaning the area can help to speed healing.
CROHN DISEASE MEDICATIONS — There are a number of medications used to treat Crohn disease. The "best" treatment approach will depend on several factors, including your age, which part of your intestine is affected, if your disease is severe, and the presence of other medical conditions you may have. The following is a summary of commonly used medications.
Steroids — Steroids, or glucocorticoids, include prednisone and budesonide. These medicines are usually used for a limited time to get inflammation under control and are then gradually stopped. Steroids are not recommended long-term because of the side effects. In addition, steroids do not heal the lining of the intestine like other therapies can.
5-aminosalicylates and sulfasalazine — The 5-aminosalicylates (abbreviated 5-ASA) and sulfasalazine are a group of medicines that reduce inflammation in the last part of the small intestine (ileum) and colon. 5-ASA medicines are used to treat ulcerative colitis (another type of inflammatory bowel disease), but in some cases can be used for treating Crohn disease. For example, sulfasalazine can be used when the inflammation is found only in the colon. (See "Patient education: Sulfasalazine and the 5-aminosalicylates (Beyond the Basics)".)
Immunomodulators — Immunomodulators help to reduce the inflammation associated with Crohn disease. Immunomodulators might be recommended if you have severe symptoms or do not improve with steroids, or if your symptoms worsen after decreasing your steroid dose. The most commonly used immunomodulators include azathioprine, 6-mercaptopurine, and methotrexate.
Biologic response modifiers — Biologic response modifiers (sometimes called "biologics") are a class of therapies that work by preventing inflammation. These therapies are often used in combination with treatments described above.
Biologic response modifiers can be expensive. They also have side effects that are different than other therapies because they are proteins rather than chemicals (see 'Side effects' below). As a result, biologic response modifiers are generally reserved for people with moderate to severe symptoms.
Biologic response modifiers are given either as an injection or through a vein (by IV); some can be given at home, while others must be given in a doctor's office or infusion center. Several biologic agents are available for treating Crohn disease, including:
●Infliximab (brand name: Remicade)
●Adalimumab (brand name: Humira)
●Certolizumab pegol (brand name: Cimzia)
●Vedolizumab (brand name: Entyvio)
●Ustekinumab (brand name: Stelara)
●Risankizumab (brand name: Skyrizi)
In some cases, "biosimilar" medications are available. These are similar but not identical to biologic response modifiers, and they may be less expensive.
Side effects — Biologic response modifiers interfere with the immune system's ability to fight infection and should not be used in people with serious infections. You will need to get tested for tuberculosis (TB) before starting treatment with one of these medicines, since treatment can "activate" TB if you have been exposed to it previously (see "Patient education: Tuberculosis (Beyond the Basics)"). Biologic response modifiers can also reactivate hepatitis B, if present, and screening for this infection is important as well. Because these therapies are proteins rather than chemicals, some people have allergic reactions to them. Symptoms of an allergic reaction can include hives, rash, joint pain, or shortness of breath or wheezing.
Biologic response modifiers are not recommended for people who currently have or have previously had lymphoma (a type of cancer). Some studies have reported an association between these drugs and a higher risk of developing lymphoma. More research is needed to determine how long a biologic response modifier can be used before the risk of lymphoma outweighs the benefits of the medication.
SURGERY FOR CROHN DISEASE — Medicines can help control the symptoms and complications of Crohn disease and can help you to avoid or postpone surgery. However, surgery may be recommended if your symptoms are not controlled with medicine or if the side effects of medicine are unbearable. About 80 percent of people with Crohn disease will need surgery at some point in their life.
It is important to have realistic expectations of surgery. Surgery does not cure Crohn disease, but it can help you to feel better and return to normal activities. The disease eventually returns after surgery, and most people will need to keep taking medicines to control symptoms over the long term. However, between 85 and 90 percent of people have no symptoms during the year following surgery. Up to 20 percent of people have no symptoms 15 years after surgery.
The most commonly performed surgeries for Crohn disease include:
●Removal of part of the small intestine and/or colon – For this procedure, the surgeon removes the diseased part of the intestine (called a resection), then rejoins the two ends (called an anastomosis). After surgery, most people are still able to have bowel movements as usual, through the anus.
In some cases, the surgeon will not be able to reconnect the two ends of the intestine. Instead, the surgeon will connect the intestines to an opening in the abdomen, called an ostomy (figure 2). Your bowel movements will exit your body through the ostomy, rather than through your anus. You will wear a plastic bag on the outside of the ostomy to collect the waste, and you will empty the bag as needed.
In most cases, the ostomy is temporary and is reversed after your bowel has healed for a few months. In other cases, a permanent ostomy is required.
The idea of an ostomy can be frightening. You will need to learn how to care for the ostomy, including how to care for the skin around the ostomy and fitting and emptying the bag that covers the ostomy. An ostomy nurse specialist is expert in the care of people with ostomies. With training, time, and support, it is possible to lead a normal life with an ostomy.
●Opening blockages – Strictureplasty is a procedure used to open blockages (strictures) in the bowel. It is sometimes done at the same time as a resection. Strictureplasty may be recommended if you have blockages in a particular part of your bowels over and over.
CROHN DISEASE AND LIFESTYLE — There might be certain foods or food groups that worsen your symptoms, particularly during flares, and it is reasonable to avoid these foods temporarily. However, eliminating entire food groups or severely restricting your diet can lead to undernutrition. Your healthcare provider or a dietitian can help you make changes to your diet to help control symptoms.
Other lifestyle recommendations include the following:
●Regular exercise is a good idea for everyone, including people with Crohn disease
●Smoking can worsen Crohn disease (ie, leads to more severe symptoms or more frequent flares) and increases your risk of needing surgery. While smoking has serious health risks for anyone, it is particularly important to avoid (or quit) smoking if you have Crohn disease. (See "Patient education: Quitting smoking (Beyond the Basics)".)
●Avoid taking nonsteroidal antiinflammatory drugs (NSAIDs) such as ibuprofen (brand names: Motrin, Advil) and naproxen (brand name: Aleve), since they can worsen the disease.
Crohn disease and colon cancer — Having Crohn disease increases your risk of developing colorectal cancer, but only in those who have Crohn disease affecting more than a third of their colon.
To find colorectal cancer as soon as possible, most experts recommend that people with Crohn disease start having colon cancer screening early and often. For some people, this might mean having a colonoscopy eight years after symptoms started, and then every one to two years thereafter. (See "Patient education: Colonoscopy (Beyond the Basics)".)
Talk to your healthcare provider to find out when you should start having colon cancer screening and how often it should be repeated. (See "Patient education: Screening for colorectal cancer (Beyond the Basics)".)
PREGNANCY AND CROHN DISEASE — If you have Crohn disease and want to get pregnant, your healthcare provider can talk to you about what to expect. More information about fertility, pregnancy, and breastfeeding in women with Crohn disease is also available separately. (See "Patient education: Inflammatory bowel disease and pregnancy (Beyond the Basics)".)
CLINICAL TRIALS — New medicines are continually being developed to treat Crohn disease. The majority of the new medicines that are being developed help control inflammation. Many of these drugs are currently undergoing clinical trials.
If you are interested in participating in a clinical trial, discuss this with your healthcare provider or read more about clinical trials on the Internet (www.clinicaltrials.gov/).
WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem.
This article will be updated as needed on our web site (www.uptodate.com/patients). Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.
Patient level information — UpToDate offers two types of patient education materials.
The Basics — The Basics patient education pieces answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials.
Patient education: Crohn disease in adults (The Basics)
Patient education: Colon and rectal cancer screening (The Basics)
Patient education: Colostomy care (The Basics)
Patient education: Colectomy (The Basics)
Patient education: Pyoderma gangrenosum (The Basics)
Patient education: Ileostomy care (The Basics)
Patient education: Crohn disease in children (The Basics)
Beyond the Basics — Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are best for patients who want in-depth information and are comfortable with some medical jargon.
Patient education: Ulcerative colitis (Beyond the Basics)
Patient education: Irritable bowel syndrome (Beyond the Basics)
Patient education: Sulfasalazine and the 5-aminosalicylates (Beyond the Basics)
Patient education: Tuberculosis (Beyond the Basics)
Patient education: Quitting smoking (Beyond the Basics)
Patient education: Colonoscopy (Beyond the Basics)
Patient education: Screening for colorectal cancer (Beyond the Basics)
Patient education: Inflammatory bowel disease and pregnancy (Beyond the Basics)
Professional level information — Professional level articles are designed to keep doctors and other health professionals up-to-date on the latest medical findings. These articles are thorough, long, and complex, and they contain multiple references to the research on which they are based. Professional level articles are best for people who are comfortable with a lot of medical terminology and who want to read the same materials their doctors are reading.
Clinical manifestations and complications of inflammatory bowel disease in children and adolescents
Clinical manifestations, diagnosis, and prognosis of Crohn disease in adults
Surveillance and management of dysplasia in patients with inflammatory bowel disease
Fertility, pregnancy, and nursing in inflammatory bowel disease
Treatment of Crohn disease in adults: Dosing and monitoring of tumor necrosis factor-alpha inhibitors
Overview of the medical management of mild (low risk) Crohn disease in adults
Overview of the management of Crohn disease in children and adolescents
Perianal Crohn disease
Dermatologic and ocular manifestations of inflammatory bowel disease
Surgical management of ulcerative colitis
Management of Crohn disease after surgical resection
The following organizations also provide reliable health information.
●National Library of Medicine
●National Institute of Diabetes and Digestive and Kidney Diseases
●Crohn's and Colitis Foundation of America