Crohn's disease

Overview

Crohn's disease is a type of inflammatory bowel disease (IBD) that causes swelling and irritation of the tissues, called inflammation, in the digestive tract. This can lead to belly pain, severe diarrhea, fatigue, weight loss and malnutrition.

Inflammation caused by Crohn's disease can affect different areas of the digestive tract in different people. Crohn's most commonly affects the end of the small intestine and the beginning of the large intestine. The inflammation often spreads into the deeper layers of the bowel.

Crohn's disease can be both painful and debilitating. Sometimes, it may lead to serious or life-threatening complications.

There's no known cure for Crohn's disease, but therapies can greatly reduce its symptoms and even bring about long-term remission and healing of inflammation. With treatment, many people with Crohn's disease can function well.

Symptoms

Symptoms of Crohn's disease typically include:

• Diarrhea.
• Fever.
• Fatigue.
• Belly pain and cramping.
• Blood in the stool.
• Mouth sores.
• Reduced appetite and weight loss.
• Pain or drainage near or around the anus due to inflammation from a tunnel into the skin, called a fistula.

Crohn's disease can affect any part of the small or large intestine. It may involve multiple segments, or it may be continuous. It most commonly involves the last part of the small intestine. In some people, the disease is only in the colon or the large intestine.

Symptoms of Crohn's disease can range from mild to severe. They usually develop gradually, but sometimes might come on suddenly, without warning. Someone with Crohn's disease also may have periods of time with no symptoms. This is known as remission.

Other symptoms

People with severe Crohn's disease also may experience symptoms outside of the intestinal tract, including:

• Inflammation of skin, eyes and joints.
• Inflammation of the liver or bile ducts.
• Kidney stones.
• Iron deficiency, called anemia.
• Delayed growth or sexual development, in children.

When to see a doctor

See a healthcare professional if you have ongoing changes in your bowel habits or if you have any symptoms of Crohn's disease, such as:

• Belly pain.
• Blood in the stool.
• Nausea and vomiting.
• Diarrhea lasting more than two weeks.
• Losing weight without trying.
• Fever in addition to any of the above symptoms.

Causes

The exact cause of Crohn's disease remains unknown. Previously, diet and stress were suspected, but now healthcare professionals know that these factors may aggravate, but don't cause, Crohn's disease. Several factors likely play a role in its development.

• Genes. More than 200 genes have been associated with Crohn's disease. However, researchers aren't exactly sure what role they play in the condition. Having one or more of these genes may make someone more likely to get Crohn's disease.
• Immune system. It's possible that bacteria, viruses or other environmental factors may trigger Crohn's disease. For example, certain bacteria in the gut microbiome are suspected to be associated with Crohn's disease, but it is unknown if these bacteria cause Crohn's disease. When the immune system tries to fight off an invading microorganism or environmental triggers, an atypical immune response causes the immune system to attack the cells in the digestive tract, too.

Risk factors

Risk factors for Crohn's disease may include:

• Family history. People with a first-degree relative, such as a parent, sibling or child, are at higher risk to have the disease. As many as 1 in 5 people with Crohn's disease has a family member with the disease.
• Age. Crohn's disease can happen at any age, but it's more common to develop the condition when you're young. Most people who develop Crohn's disease are diagnosed before they're around 30 years old.
• Ethnicity. Although Crohn's disease can affect any ethnic group, white people have the highest risk, especially people of Eastern European (Ashkenazi) Jewish descent. However, the incidence of Crohn's disease is increasing among Black people who live in North America and the United Kingdom. Crohn's disease also is being increasingly seen in the Middle Eastern population and among migrants to the United States.
• Cigarette smoking. Cigarette smoking is the most important controllable risk factor for developing Crohn's disease. Smoking also leads to more-serious disease and a greater risk of having surgery. If you smoke, it's important to stop.
• Nonsteroidal anti-inflammatory medicines. These include ibuprofen (Advil, Motrin IB, others), naproxen sodium (Aleve), diclofenac sodium and others. While they do not cause Crohn's disease, they can lead to inflammation of the bowel that makes Crohn's disease worse.

Complications

Crohn's disease may lead to one or more of the following complications:

• Bowel blockage or obstruction. Crohn's disease can affect the entire thickness of the intestinal wall. Over time, parts of the bowel can scar and narrow, which may block the flow of digestive contents, often known as a stricture. Surgery to widen the stricture or to remove the diseased portion of the bowel may be necessary.
• Ulcers. Ongoing inflammation can lead to open sores called ulcers anywhere in the digestive tract. This can include the mouth, anus and genital area.

• Fistulas. Sometimes ulcers can extend completely through the intestinal wall, creating a connection between different body parts that shouldn't be there. This is known as a fistula. Fistulas can develop between the intestine and the skin, or between the intestine and another organ. Fistulas near or around the anal area are the most common kind.

  When fistulas develop inside the abdomen, it may lead to infections and collections of pus called abscesses. This can be life-threatening if not treated. Fistulas may form between loops of bowel, in the bladder or vagina, or through the skin, causing continuous drainage of bowel contents to the skin.

• Anal fissure. This is a small tear in the tissue that lines the anus or in the skin around the anus where infections can occur. It's often associated with painful stool and may lead to a fistula.
• Malnutrition. Diarrhea, belly pain and cramping may make it difficult to eat or for the intestine to absorb enough nutrients. It's also common to develop anemia due to low iron or vitamin B-12 caused by the disease.

• Colon cancer. Having Crohn's disease that affects the colon increases the risk of colon cancer. General colon cancer screening guidelines for people without Crohn's disease call for a colonoscopy at least every 10 years beginning at age 45.

  In people with Crohn's disease affecting a large part of the colon, a colonoscopy to screen for colon cancer is recommended about eight years after disease onset and generally is performed every 1 to 2 years afterward. Ask a healthcare professional whether you need to have this test done sooner and more frequently.

• Skin disorders. Many people with Crohn's disease also may develop a condition called hidradenitis suppurativa. This skin disorder involves deep nodules, tunnels and abscesses in the armpits, groin, under the breasts, and in the perianal or genital area. Some Crohn's disease treatments also increase the risk of skin cancers, so a routine skin examination is recommended.
• Other health problems. Crohn's disease also can cause problems in other parts of the body. Among these problems are low iron, called anemia, osteoporosis, arthritis, kidney stones, eye problems, and gallbladder or liver disease.

• Medicine risks. Certain Crohn's disease medicines that block functions of the immune system are associated with a small risk of developing cancers, including lymphoma and skin cancers. They also increase the risk of infections.

  Corticosteroids can be associated with a risk of osteoporosis, bone fractures, cataracts, glaucoma, diabetes and high blood pressure, among other conditions. Work with a healthcare professional to determine risks and benefits of medicines.

• Blood clots. Crohn's disease increases the risk of blood clots in veins and arteries.

Diagnosis

A healthcare professional will likely diagnose Crohn's disease only after ruling out other possible causes for symptoms. There is no single test to diagnose Crohn's disease.

A combination of tests may be used to help confirm a diagnosis of Crohn's disease, including:

Lab tests

• Blood tests. Blood tests can check for signs of infection or anemia — a condition in which there aren't enough red blood cells to carry enough oxygen to the tissues.

  These tests also may be used to check for levels of inflammation, liver function or the presence of inactive infections, such as tuberculosis. Blood also may be screened for the presence of immunity against infections.

• Stool studies. A stool sample may be used to test for blood or organisms, such as infection-causing bacteria or, rarely, parasites in the stool, to look for causes of diarrhea and symptoms. Sometimes looking for stool markers of inflammation, such as calprotectin, can be helpful.

Procedures

• Colonoscopy. A colonoscopy uses a tiny camera on the end of a flexible tube to visually examine the entire colon and the very end of the ileum. During the procedure, small samples of tissue, called a biopsy, may be taken for laboratory analysis. This may help to make a diagnosis. Clusters of inflammatory cells called granulomas may suggest a diagnosis of Crohn's disease.

• CT scan. A CT scan is a special X-ray technique that provides more detail than a standard X-ray does. This test looks at the entire bowel as well as at tissues outside the bowel.

  CT enterography is a special CT scan that involves drinking an oral contrast material and getting intravenous contrast images of the intestines. This test provides better images of the small bowel and has replaced barium X-rays in many medical centers.

• MRI. An MRI scan uses a magnetic field and radio waves to create detailed images of organs and tissues. MRI used with a contrast fluid, called MR enterography, is particularly useful for evaluating a fistula around the anal area or the small intestine.

  Sometimes MR enterography can be performed to check for disease status or progression. This test may be used instead of CT enterography to reduce the risk of radiation, especially in younger people.

• Capsule endoscopy. This test involves swallowing a capsule with a camera in it. The camera takes pictures of the small intestine and sends them to a recorder worn on a belt. The images are then downloaded to a computer, displayed on a monitor and checked for signs of Crohn's disease. The camera exits the body painlessly in stool.

  Endoscopy with biopsy may still be necessary to confirm a diagnosis of Crohn's disease. Those with Crohn's disease of the small intestine may be at a higher risk of the capsule getting stuck in the intestine, especially if there is a history of narrowing or surgery of the small intestine. Capsule endoscopy should not be done if there is a suspected stricture or blockage, also called an obstruction, in the bowel.

Treatment

There is currently no cure for Crohn's disease, and there is no single treatment that works for everyone. However, there are several medicines that have been approved for treatment of Crohn's disease. One goal of medical treatment is to reduce the inflammation that triggers symptoms. Another goal is to improve long-term prognosis by limiting complications. In the best cases, this may lead not only to symptom relief but also to long-term remission.

Anti-inflammatory medicines

Anti-inflammatory medicines are often the first step in the treatment of inflammatory bowel disease. They include:

• Corticosteroids. Corticosteroids such as prednisone and budesonide (Entocort EC) can help reduce inflammation in the body, but they don't work for everyone with Crohn's disease. Sometimes, intravenous steroids are used in the hospital setting for short duration.

  Corticosteroids may be used for short term (3 to 4 months) symptom improvement and to induce remission. Corticosteroids also may be used in combination with an immune system suppressor to induce the benefit from other medicines. They are then eventually tapered off.

• Oral 5-aminosalicylates. These medicines are sometimes used for mild to moderate Crohn's disease. They include sulfasalazine (Azulfidine), which contains sulfa, and mesalamine (Delzicol, Pentasa, others). Oral 5-aminosalicylates work best for Crohn's disease in the colon but don't work as well if the disease is in the small intestine.

Immune system suppressors

These drugs also reduce inflammation, but they target your immune system, which produces the substances that cause inflammation. For some people, a combination of these drugs works better than one drug alone.

Immune system suppressors include:

• Azathioprine (Azasan, Imuran) and mercaptopurine (Purinethol, Purixan). These are the most widely used immunosuppressants for treatment of inflammatory bowel disease. Taking them requires that you follow up closely with a healthcare professional and have your blood checked regularly. This is to look for side effects, such as a lowered resistance to infection and inflammation of the liver. These medicines also may cause nausea and vomiting.
• Methotrexate (Trexall). This medicine is sometimes used for people with Crohn's disease who don't respond well to other medicines. You will need to be followed closely for side effects.

Biologics

This class of therapies targets proteins made by the immune system. Types of biologics used to treat Crohn's disease include:

• Infliximab (Remicade), adalimumab (Humira) and certolizumab pegol (Cimzia). Also known as TNF inhibitors, these medicines work by neutralizing an immune system protein known as tumor necrosis factor (TNF).
• Ustekinumab (Stelara). This treats Crohn's disease by interfering with the action of an interleukin, which is a protein involved in inflammation.
• Vedolizumab (Entyvio). This is a type of medicine known as a monoclonal antibody. It works by stopping certain immune cell molecules — integrins — from binding to other cells in the intestinal lining. Vedolizumab is a gut-specific agent and is approved for Crohn's disease.
• Risankizumab (Skyrizi). Risankizumab also is a monoclonal antibody. This medicine acts against a molecule known as interleukin-23. Risankizumab was recently approved for treating moderate to severe Crohn's disease.

Synthetic versions of biologics, called biosimilars, are available to treat Crohn's disease. These medicines work like the original versions of biologics, and they may cost less.

Janus kinase (JAK) inhibitors

JAK inhibitors are a type of medicine known as small molecules. These newer medicines help reduce inflammation by targeting parts of the immune system that cause inflammation in the intestines. They are taken by mouth. JAK inhibitors may be recommended for Crohn's disease that hasn't responded to other therapies. The U.S. Food and Drug Administration has approved the JAK inhibitor upadacitinib to treat Crohn's disease. JAK inhibitors are not recommended for use in pregnancy.

Antibiotics

Antibiotics can reduce the amount of drainage from fistulas and abscesses and sometimes heal them in people with Crohn's disease. Some researchers also think that antibiotics help reduce harmful bacteria that may be causing inflammation in the intestine. Commonly prescribed antibiotics include ciprofloxacin (Cipro) and metronidazole (Flagyl).

Other medicines

In addition to controlling inflammation, some medicines may help relieve symptoms. But talk to a healthcare professional before taking any medicines you can buy without a prescription. Depending on the severity of Crohn's disease, a health professional may recommend one or more of the following:

• Anti-diarrheals. A fiber supplement, such as psyllium husk (Metamucil) or methylcellulose (Citrucel), can help relieve mild to moderate diarrhea by adding bulk to stool. For more severe diarrhea, loperamide (Imodium A-D) may be effective.

  These medicines could be ineffective or even harmful in some people with strictures or certain infections. Please consult a healthcare professional before taking these medicines.

• Pain relievers. For mild pain, a health professional may recommend acetaminophen (Tylenol, others) — but not other common pain relievers, such as ibuprofen (Advil, Motrin IB, others) or naproxen sodium (Aleve). These medicines are likely to make symptoms worse and can make the disease worse as well.
• Vitamins and supplements. If you're not absorbing enough nutrients, your health professional may recommend vitamins and nutritional supplements.

Nutrition therapy

A health professional may recommend a special diet given by mouth or a feeding tube, called enteral nutrition. Nutrients also can be delivered into a vein, called parenteral nutrition. This can improve overall health and allow the bowel to rest. Bowel rest may reduce inflammation in the short term.

Your care professional may use nutrition therapy short term and combine it with medicines, such as immune system suppressors. Enteral and parenteral nutrition are typically used to get people healthier before surgery or when other medicines fail to control symptoms.

Your care professional also may recommend a low residue or low-fiber diet to reduce the risk of intestinal blockage if you have a narrowed bowel, called a stricture. A low residue diet is designed to reduce the size and number of your stools.

Surgery

If diet and lifestyle changes, medicines, or other treatments don't relieve symptoms, a healthcare professional may recommend surgery. Nearly half of those with Crohn's disease might require at least one surgery. However, surgery does not cure Crohn's disease.

During surgery, the surgeon removes a damaged portion of your digestive tract and then reconnects the healthy sections. Surgery also may be used to close fistulas and drain abscesses.

The benefits of surgery for Crohn's disease are usually temporary. The disease often recurs, often near the reconnected tissue. The best approach is to follow surgery with medicine to reduce the risk of recurrence.

Lifestyle and home remedies

Sometimes you may feel helpless when facing Crohn's disease. But changes in your diet and lifestyle may help control your symptoms and lengthen the time between flare-ups.

Diet

There's no firm evidence that what you eat causes inflammatory bowel disease. But certain foods and beverages can aggravate your symptoms, especially during a flare-up.

It can be helpful to keep a food diary to track what you're eating, as well as how you feel. If you discover that some foods are causing your symptoms to flare, you can try eliminating them.

Here are some general dietary suggestions that may help to manage your condition:

• Limit dairy products. Many people with inflammatory bowel disease find that problems such as diarrhea, belly pain and gas improve by limiting or eliminating dairy products. You may be lactose intolerant — that is, your body can't digest the milk sugar, called lactose, in dairy foods. Using an enzyme product such as Lactaid may help.
• Eat small meals. You may feel better eating five or six small meals a day rather than two or three larger ones.
• Drink plenty of liquids. Try to drink plenty of fluids daily. Water is best. Alcohol and beverages that contain caffeine stimulate your intestines and can make diarrhea worse, while carbonated drinks frequently produce gas.
• Consider multivitamins. Because Crohn's disease can interfere with your ability to absorb nutrients and because your diet may be limited, multivitamin and mineral supplements are often helpful. Check with a healthcare professional before taking any vitamins or supplements.
• Talk to a dietitian. If you begin to lose weight or your diet has become very limited, talk to a registered dietitian.

Smoking

Smoking increases your risk of developing Crohn's disease. And once you have Crohn's disease, smoking can make it worse. People with Crohn's disease who smoke are more likely to have relapses and need medicines and repeat surgeries. Quitting smoking can improve the overall health of your digestive tract, as well as provide many other health benefits.

Stress

Although stress doesn't cause Crohn's disease, it can make your symptoms worse and may trigger flare-ups. Although it's not always possible to avoid stress, you can learn ways to help manage it, such as:

• Exercise. Even mild exercise can help reduce stress, relieve depression and regulate bowel function. Talk to a healthcare professional about an exercise plan that's right for you.
• Biofeedback. This stress-reduction technique may help you decrease muscle tension and slow your heart rate with the help of a feedback machine. The goal is to help you enter a relaxed state so that you can cope more easily with stress.
• Regular relaxation and breathing exercises. One way to cope with stress is to regularly relax and use techniques such as deep, slow breathing to calm down. Many helpful books and online videos are available to help with relaxation and meditation.

Alternative medicine

Many people with Crohn's disease have used some form of complementary and alternative medicine to treat their condition. However, there are few well-designed studies of the safety and effectiveness of these treatments.

Coping and support

Crohn's disease doesn't just affect you physically — it takes an emotional toll as well. If signs and symptoms are severe, your life may revolve around a constant need to run to the toilet. Even if your symptoms are mild, gas and abdominal pain can make it difficult to be out in public. All of these factors can alter your life and may lead to depression. Here are some things you can do:

• Be informed. One of the best ways to be more in control is to find out as much as possible about Crohn's disease. Look for information from the Crohn's & Colitis Foundation.
• Join a support group. Although support groups aren't for everyone, they can provide valuable information about your condition as well as emotional support. Group members frequently know about the latest medical treatments or integrative therapies. You may also find it reassuring to be among others with Crohn's disease.
• Talk to a therapist. Some people find it helpful to consult a mental health professional who's familiar with inflammatory bowel disease and the emotional difficulties it can cause.

Although living with Crohn's disease can be discouraging, research is ongoing and the outlook is improving.

Preparing for an appointment

Symptoms of Crohn's disease may first prompt you to visit your primary healthcare professional. Your care professional may recommend that you see a specialist who treats digestive diseases, called a gastroenterologist.

Because appointments can be brief, and there's often a lot of information to discuss, it's a good idea to be well prepared. Here's some information to help you get ready, and what to expect from your visit.

What you can do

• Be aware of any pre-appointment restrictions. At the time you make the appointment, be sure to ask if there's anything you need to do in advance, such as restrict your diet.
• Write down any symptoms you're experiencing, including any that may seem unrelated to the reason for which you scheduled the appointment.
• Write down key personal information, including any major stresses or recent life changes.
• Make a list of all medicines, vitamins or supplements that you're taking.
• Ask a family member or friend to come with you to your appointment. Sometimes it can be difficult to take in all the information provided during an appointment. Someone who accompanies you may remember something that you missed or forgot.

Preparing a list of questions before you go can help you make the most of your visit. List your questions from most important to least important in case time runs out. For Crohn's disease, some basic questions to ask include:

• What's causing these symptoms?
• Are there other possible causes for my symptoms?
• What kinds of tests do I need? Do these tests require any special preparation?
• Is this condition temporary or long lasting?
• What treatments are available, and which do you recommend?
• Are there any medicines that I should avoid?
• What types of side effects can I expect from treatment?
• Are there any alternatives to the approach that you're suggesting?
• I have other health conditions. How can I best manage them together?
• Do I need to follow any dietary restrictions?
• Is there a generic alternative to the medicine you're prescribing me?
• Are there any brochures or other printed material that I can take with me? What websites do you recommend?
• If I have Crohn's disease, what is the risk that my child will develop it?
• What kind of follow-up testing do I need in the future?

In addition to the questions that you've prepared, don't hesitate to ask additional questions during your appointment.

What to expect from your doctor

You'll likely be asked a number of questions, including:

• When did you first begin experiencing symptoms?
• Have your symptoms been continuous or off and on?
• How severe are your symptoms?
• Do your symptoms affect your ability to work or do other activities?
• Does anything seem to improve your symptoms?
• Is there anything that you've noticed that makes your symptoms worse?
• Do you smoke?
• Do you take over the counter or prescription nonsteroidal anti-inflammatory medicines (NSAIDs) — for example, ibuprofen (Advil, Motrin IB, others), naproxen sodium (Aleve) or diclofenac sodium?