Crohn's Disease

What is Crohn's disease?

Crohn's disease occurs when there is redness and swelling (inflammation) and sores along your digestive tract. It is part of a group of diseases known as inflammatory bowel disease or IBD.

Crohn's disease is a long-term, chronic illness that may come and go at different times in your life. In most cases, it affects the small intestine, most often the lower part called the ileum. In some cases, it affects both the small and large intestines.

Sometimes the inflammation may be along your whole digestive tract. This includes your mouth, your food pipe (esophagus), your stomach, the first part of your small intestine or duodenum, the jejunum, your appendix, and your anus.

What causes Crohn's disease?

Experts don’t know what causes Crohn's disease. It may be that a virus or a bacterium affects the body's infection-fighting system (immune system). The immune system may create an abnormal inflammation reaction in the intestinal wall that does not stop.

Many people with Crohn's disease have abnormal immune systems. But experts don’t know if immune problems cause the disease. They also don’t know if Crohn's disease may cause immune problems. Stress does not seem to cause Crohn's disease.

Who is at risk for Crohn's disease?

Crohn's disease may happen at any age. It most often affects people ages 15 to 35. It can also happen in children or older adults. It affects men and women equally.

You may be more at risk for Crohn's disease if you:

  • Have a family history of Crohn's disease, such as your father, mother, brother, sister, or child

  • Have an Eastern European background, especially Jews of European descent

  • Are white. But Crohn's disease is becoming more common in many ethnic groups.

  • Live in a developed country, in a city, or in a northern climate

  • Smoke

What are the symptoms of Crohn's disease?

Each person’s symptoms may vary. Symptoms may include:

  • Belly or abdominal pain, often in the lower right area

  • Diarrhea, sometimes bloody

  • Rectal bleeding

  • Weight loss

  • Feeling tired

  • Fever

  • Joint pain

  • Anemia

  • Nausea or vomiting

  • Loss of appetite

  • A cut or tear in the anus (anal fissure)

  • Rashes

You may have no symptoms for a long time, even years. That is called being in remission. There is no way to know when remission may occur or when your symptoms will return.

The symptoms of Crohn's disease may look like other health problems. Always see your healthcare provider to be sure.

How is Crohn's disease diagnosed?

You may be checked for signs of Crohn's disease if you have had long-term or chronic:

  • Belly or abdominal pain

  • Diarrhea

  • Fever

  • Weight loss

  • Anemia, a loss of healthy red blood cells that can make you feel tired

Your healthcare provider will look at your past health and give you a physical exam.

Other tests for Crohn's disease may include the following:

  • Blood tests. These are done to see if you have fewer healthy red blood cells (anemia) because of a loss of blood. These tests also check if you have a higher number of white blood cells. That might mean you have an inflammatory problem.

  • Stool culture. This is done to see if you have any abnormal bacteria in your digestive tract that may cause diarrhea or other problems. A small sample of your stool is collected and sent to a lab. In 2 or 3 days, the test will show if you have abnormal bacteria or if you have lost blood. It will also show if an infection by a parasite or bacteria is causing your symptoms.

  • Other stool tests. Besides a stool culture, other stool sample tests like a fecal calprotectin or lactoferrin may be done to see if there is inflammation in your intestine.

  • Upper endoscopy. This test looks at the inside of your food pipe or esophagus, stomach, and the top part of your small intestine, called the duodenum. This test uses a thin, lighted tube called an endoscope. The tube has a camera at one end. While you are sedated, the tube is put into your mouth and throat. Then it goes into your esophagus, stomach, and duodenum. Your healthcare provider can see the inside of these organs. They can also take a small tissue sample or biopsy if needed.

  • Colonoscopy. This test looks at the full length of your large intestine. It can help check for any abnormal growths, tissue that is red or swollen, sores, or bleeding. A long, flexible, lighted tube with a tiny camera on the end (colonoscope) is used. While you are sedated, it is put into your rectum up into the colon. This tube lets your healthcare provider see the lining of your colon and take out a tissue sample or biopsy to test it. They may also be able to treat some problems that may be found.

  • Biopsy. Your healthcare provider will take a sample of tissue or cells from the lining of your colon to have it looked at under a microscope.

  • Upper GI series or barium swallow. This test looks at the organs that make up the top part of your digestive system. It checks your esophagus, stomach, and the first part of your small intestine, called the duodenum. You will swallow a chalky fluid called barium. Barium coats the organs so that they can be seen on an X-ray. Then X-rays are taken to check your digestive organs.

  • Lower GI series or barium enema. This test checks your large intestine, including the colon and rectum. A thick, chalky fluid called barium is put into a tube. It is inserted into your rectum as an enema. Barium coats the organs so they can be seen on an X-ray. An X-ray of your belly will show any narrowed areas, called strictures. It will also show any blockages or other problems.

  • CT scan. This test uses X-ray images to create a view of the abdomen and pelvis structures. It may be done with IV or oral X-ray contrast. A type of CT scan called CT enterography looks at the intestine.

  • MRI. This test uses a magnetic field and radio waves to create a view of the abdomen, pelvis, and intestine. It may be done with IV contrast and, in some cases, rectal contrast.

  • Capsule endoscopy. For this test, you swallow a small pill (capsule) that is a video camera. It takes pictures of the small intestine as it passes through. The capsule is passed naturally in your stool, and pictures from the monitor are evaluated on a computer.

How is Crohn's disease treated?

Treatment will depend on your symptoms, age, and general health. It will also depend on how severe the condition is.

There is no cure for Crohn's disease. But there are some things that can help to control it. The goal of treatment is remission. This means you no longer have symptoms of Crohn's disease. Treatment has three parts:

  • Ease symptoms, such as belly or abdominal pain, diarrhea, and rectal bleeding

  • Control redness or swelling (inflammation)

  • Help you get the right nutrition

Treatment may include:

  • Medicine. Some medicines may help ease abdominal cramps and diarrhea. Medicines often reduce inflammation in the colon. If you have a more serious case, you may need medicines that affect your body's infection-fighting system (immune system). These medicines are called biologics. They are given as pills, injections, or combinations of both. It is very important to discuss the pros and cons of medicine with your healthcare provider and to not stop taking the medicine without their knowledge. Sometimes stopping a medicine will limit its ability to help you again in the future.

  • Diet. No special diet has been shown to help prevent or treat Crohn's disease. However, a special diet called an elemental diet can treat Crohn's disease in some situations. In some cases, symptoms are made worse by milk, alcohol, hot spices, or fiber.

  • Supplements. Your healthcare provider may suggest nutritional supplements or special, high-calorie liquid formulas. These may be helpful for children who are not growing fast enough.

  • IV or intravenous feeding. In rare cases, IV feeding may be used for people who need extra nutrition for a short period of time.

  • Surgery. Surgery may help Crohn's disease, but it can’t cure it. The swelling or inflammation often returns next to the area where the intestine was removed. Sometimes surgery is also needed to treat sores around the anus.

  • Lifestyle changes. Think about the following:

    • If you smoke, stop. Smoking makes Crohn's disease symptoms worse.

    • If stress and emotions make your symptoms worse, counseling may help. So can self-help measures, such as exercise, yoga, and meditation.

Surgery choices

Surgery may help to reduce long-term or chronic symptoms that don’t get better with therapy. Surgery may also fix some problems, such as a blocked intestine, a narrowed area (stricture), a hole or perforation, an abscess, or bleeding.

Types of surgery may include:

Draining abscesses in or near fistulas

An abscess is a collection of pus or infection. Treatment includes antibiotics and injectables, such as biologics, but sometimes surgery is needed.

Bowel or intestinal resection

The diseased section of intestine is removed. The two healthy pieces of intestine are attached. This surgery shortens your intestines.


When part of the intestine is removed, a new opening is made to remove stool from your body. The surgery to create the new opening is called an ostomy. The new opening is called a stoma. There are different types of ostomy surgery. The type of surgery that is done will depend on how much and what part of your intestines is removed.

Ostomy surgery may include:

  • Ileostomy. The colon and rectum are removed, and the bottom part of your small intestine (ileum) is attached to the new opening or stoma.

  • Colostomy. This surgery creates an opening in your belly or abdomen. A small part of the colon goes through this opening up to the surface of the skin. In some cases, a short-term colostomy may be done. This is used when part of the colon has been removed and the rest of the colon needs to heal.

  • Ileoanal reservoir surgery. This may be done instead of a permanent ileostomy. It is done in two surgeries. First, the colon and rectum are removed, and a short-term ileostomy is performed. Then, the ileostomy is closed. Part of the small intestine is used to create an internal pouch to hold stool. This pouch is attached to the anus. The muscle of the rectum is left in place so that the stool in the pouch does not leak out of the anus. People who have this surgery are able to control their bowel movements.

What are possible complications of Crohn's disease?

Crohn's disease may cause other health problems. These may include:

  • A blocked (intestinal obstruction) or narrowed (stricture) intestine

  • A type of tunnel, called a fistula, in nearby tissues, which can get infected

  • Rips or tears, called fissures, in your anus

  • Colon cancer, if your colon is involved with the Crohn's disease

  • Problems with your liver function

  • Gallstones

  • A lack of some nutrients, such as calories, proteins, and vitamins

  • Too few red blood cells or too little hemoglobin in your blood (anemia)

  • Bone weakness, either because bones are brittle (osteoporosis) or because bones are soft (osteomalacia)

  • A nervous system disorder where legs feel painful, called restless leg syndrome

  • Arthritis

  • Skin problems

  • Eye or mouth redness or swelling (inflammation)

Crohn's disease can also lead to a condition called malabsorption. The intestines help to digest and absorb foods. Malabsorption happens when food is not digested well and nutrients are not absorbed into the body. This can lead to poor growth and development. Malabsorption may happen when the digestive tract is inflamed or if short bowel syndrome occurs after surgery.

Common symptoms of malabsorption include the following:

  • Loose stool or diarrhea

  • Large amounts of fat in the stool called steatorrhea

  • Weight loss or poor growth

  • Fluid loss or dehydration

  • Lack of vitamins and minerals

It is important to treat Crohn's disease. This means not stopping the medicines when you feel better. This is because keeping the disease under control (remission) is the best way to prevent complications many years later.

What can I do to prevent Crohn's disease?

Experts don’t know what causes Crohn's disease or how it can be prevented.

Living with Crohn's disease

It’s important for you to work closely with your healthcare provider to manage your disease. Make sure to keep your regular visits with your healthcare provider since ongoing observation is important. Follow all instructions about medicines, diet, and lifestyle changes.

When should I call my healthcare provider?

Call your healthcare provider if your symptoms get worse or you have new symptoms.

Key points about Crohn's disease

  • Crohn's disease is when there is redness and swelling (inflammation) and sores or ulcers along your digestive tract.

  • It is a type of inflammatory bowel disease (IBD).

  • In most cases, it affects the small intestine. But it may affect your whole digestive tract.

  • It is a long-term, chronic condition.

  • There is no cure. Making some diet changes may help ease symptoms.

  • Most people with Crohn's disease need to stay on medicines long term to limit the development of other medical problems in the future. Surgery may be needed.

Next steps

Tips to help you get the most from a visit to your healthcare provider:

  • Know the reason for your visit and what you want to happen.

  • Before your visit, write down questions you want answered.

  • Bring someone with you to help you ask questions and remember what your provider tells you.

  • At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you.

  • Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.

  • Ask if your condition can be treated in other ways.

  • Know why a test or procedure is recommended and what the results could mean.

  • Know what to expect if you do not take the medicine or have the test or procedure.

  • If you have a follow-up appointment, write down the date, time, and purpose for that visit.

  • Know how you can contact your provider if you have questions.

Online Medical Reviewer: Jen Lehrer MD
Online Medical Reviewer: L Renee Watson MSN RN
Online Medical Reviewer: Raymond Turley Jr PA-C
Date Last Reviewed: 4/1/2023
© 2000-2024 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.