What I need to know about
 

Crohn’s Disease

NATIONAL INSTITUTES OF HEALTH 

National Digestive Diseases Information Clearinghouse 

Crohn’s Disease
 

U.S. Department 

of Health and 

Human Services

What I need to know about 

Crohn’s Disease 

NATIONAL INSTITUTES OF HEALTH 

National Digestive Diseases Information Clearinghouse 

Contents 

What is Crohn’s disease? ........................................ 1 

Who gets Crohn’s disease? ..................................... 2 

What are the symptoms of 

Crohn’s disease? ...................................................... 2 

What causes Crohn’s disease?................................ 3
 

How is Crohn’s disease diagnosed? ....................... 4
 

What are the complications 


of Crohn’s disease?.................................................. 6
 

How is Crohn’s disease treated? ............................ 7
 

Glossary .................................................................. 13
 

For More Information........................................... 14
 

Acknowledgments ................................................. 15
 

What is Crohn’s disease? 

Crohn’s disease causes inflammation of parts of 

the digestive tract. Inflammation is irritation and 

swelling. The inflammation, mostly caused by 

sores called ulcers, can cause pain and diarrhea. 

The digestive tract is the pathway food travels 

through in the body. This pathway is also called 

the gastrointestinal, or GI, tract. It goes from the 

mouth to the anus. Crohn’s disease can sometimes 

be hard to diagnose because its symptoms are like 

the symptoms of other GI diseases. 

Crohn’s disease can affect any area of the GI tract, 

but it most often affects a part of the small 

intestine called the ileum.* 

Normal 

Inflamed 

In Crohn’s disease, portions of the digestive tract become 

inflamed. The diseased lining of the digestive tract 

becomes swollen and scarred. 

*Words in bold type are defined in the glossary on 

page 13. 

1 
Normal digestive tract Swollen digestive tract 

Swelling in the digestive tract makes the passage narrow. 

Who gets Crohn’s disease? 

Crohn’s disease can run in families. As many 

as 20 percent of people with Crohn’s disease 

have a relative with Crohn’s disease or another 

inflammatory bowel disease. It is most common in 

people between the ages of 20 and 30. Both men 

and women can have Crohn’s disease. 

What are the symptoms of Crohn’s
 

disease?
 

Crohn’s disease symptoms can be different for each 

person. The most common symptoms of Crohn’s 

disease are abdominal pain and diarrhea. Some 

people have bleeding in the rectum, which is the 

lower end of the GI tract, just before the anus. 

Rectal bleeding can be serious and may not stop 

2 
without medical help. Bleeding can lead to 

anemia, meaning the body has lost too many red 

blood cells. Anemia makes a person feel tired. 

People can also have weight loss, skin problems, 

and fevers. Children with Crohn’s disease may 

develop and grow slower than most other children 

or they may not reach their expected full height. 

What causes Crohn’s disease? 

Scientists have many ideas about what causes 

Crohn’s disease. The immune system in people 

with Crohn’s disease may mistake bacteria and 

foods as being “invaders.” The immune system 

then attacks these invaders, causing white blood 

cells to gather in the lining of the intestines. 

This “gathering” leads to swelling and intestinal 

damage. 

The immune system’s response to these invaders 

may be either a cause or a result of the disease. 

Many things are associated with inflammation in 

the GI tract, such as 

●	 a person’s genes 

●	 the immune system not being able to recognize 

harmless GI bacteria 

●	 unknown triggers caused by the environment 

3 
How is Crohn’s disease diagnosed? 

A detailed personal history, a physical exam, and tests 

are needed to diagnose Crohn’s disease. During your 

visit the doctor will ask about your symptoms and 

health. The doctor may run blood tests. You may 

also be asked for a stool sample. 

Blood tests can uncover anemia. Anemia can mean 

you have bleeding in your intestines. Blood tests can 

also show a high white blood cell count, a sign of 

inflammation in the body. A stool sample can be 

used to check if you have bleeding and rule out an 

infection. 

4 
X rays may be needed. The doctor may also do an 

upper GI series and small bowel follow-through to 

look at your small intestine. For this test, you will 

drink barium, a chalky liquid. The barium looks 

white on x-ray film, helping the doctor see ulcers or 

other problems. 

The doctor may also do a sigmoidoscopy or a 

colonoscopy to get a better look inside the 

intestines. For both tests, the doctor places a long 

tube into the anus. The tube travels through about 

3 feet of the large intestine and sometimes into the 

very end of your small intestine. The doctor can 

see any inflammation, ulcers, or bleeding because 

the tube is linked to a TV screen that shows 

pictures of the intestines. 

The doctor may also do a biopsy. A biopsy is when 

the doctor snips a bit of tissue, in this case, from 

the lining of the intestine. The doctor will look at 

the tissue with a microscope to confirm the 

diagnosis of Crohn’s disease. You will be given 

medicine to make you sleepy during the procedure. 

You will not feel the biopsy. 

5 
What are the complications of Crohn’s 

disease? 

Intestinal blockage can occur in people with 

Crohn’s disease. Blockage occurs because the 

intestinal wall thickens or swells from inflammation 

and scar tissue. Ulcers can also cause tunnels to 

form through the inflamed areas of the intestine 

or even the healthy parts. These tunnels are called 

fistulas. Sometimes pockets of infection, called 

abscesses, can form in and around the fistulas. 

Fistulas can be treated with medicine, but 

sometimes surgery is needed. 

People with Crohn’s disease often don’t get the 

nutrients they need. If you have Crohn’s disease, 

you may not get enough protein, vitamins, or 

calories in your diet. If you aren’t getting 

nutrients, it may be because you 

●	 have an upset stomach that keeps you from 

eating enough 

●	 may be losing protein in the intestine 

●	 may not be able to absorb nutrients from 

your food 

6 
Other problems that some people with Crohn’s 

disease suffer from are arthritis, skin problems, 

swelling in the eyes or mouth, kidney stones, and 

gallstones. Some of these problems go away during 

treatment. But some must be treated with additional 

medicines. 

How is Crohn’s disease treated? 

Treatment for Crohn’s disease depends on 

●	 where the disease is located 

●	 how bad the disease is 

●	 what problems you already have from the disease 

● what past treatments you have had 

The goals of treatment are to 

●	 help the inflammation 

●	 correct nutritional problems 

●	 relieve symptoms such as abdominal pain, 

diarrhea, and rectal bleeding 

7 
Treatment may include 

● drugs 

● minerals and vitamins 

● surgery 

● nutritional support 

8 
Drug Treatment 

The doctor may first treat your Crohn’s disease 

with anti-inflammatory drugs. These drugs help 

stop inflammation and help relieve the pain and 

diarrhea. Sometimes these drugs cause side 

effects, so you should talk with your doctor 

about what to expect. 

Your doctor may also need to treat you with 

steroids. Steroids are made from natural chemicals 

in the body. However, steroids are used only for a 

short time because long-term exposure is not good 

for a person. 

9 
Immune system suppressors are also used. They 

work by keeping your body from attacking itself. 

Ask your doctor about side effects. 

Your doctor may also prescribe infliximab 

(Remicade) or adalimumab (Humira). Remicade 

and Humira are very strong drugs that need to be 

given by an injection in the vein. You can speak 

with your doctor and discuss if one of these drugs 

is right for you. 

The goal for using these drugs is to avoid long-term 

steroid use, to get you better, and keep you better. 

Diet 

No foods are known to cause injury or 

inflammation to the bowel. But when people have 

Crohn’s disease, hot spices, alcohol, greasy foods, 

and sometimes milk products may make diarrhea 

and abdominal pain worse. Your doctor may start 

you on a special diet so you get extra nutrients. 

High-calorie liquid supplements are often used to 

give you the extra calories and right amount of 

vitamins and minerals to keep you healthy. 

10 
Surgery 

Some people with Crohn’s disease may need 

surgery to treat blockage, fistulas, infection, 

and bleeding if medicines are no longer working. 

Surgery usually does not make a person disease-free 

forever. Sometimes people need to have many 

surgeries because the inflammation and symptoms 

come back. 

The most common surgery for Crohn’s disease is 

removing only the diseased section of intestine. 

In this operation, after the diseased piece of 

the intestine is cut out, the intestine is put 

back together. 

On rare occasions the surgeon cannot put the 

two ends back together and needs to create an 

outlet, or stoma, also called an ostomy. To create 

a stoma, an end of the small intestine that was not 

connected is brought out through a small opening 

made on the lower abdominal wall. The stoma is 

about the size of a quarter. A small bag is worn 

over the opening to collect waste, and the person 

empties the bag as needed. 

11 
People who have Crohn’s disease involving all or 

part of the large intestine may need to have their 

entire colon removed in an operation called a 

colectomy. If the whole colon is removed, a 

stoma is usually needed. 

Because people can have symptoms even after 

surgery, they should talk with their doctor and 

other patients before making a choice. People 

should know what to expect from surgery and 

decide what drugs, if any, would work best 

afterwards to try to stop the disease from 

coming back. Groups for people with Crohn’s 

disease can help a person find support. 

People with Crohn’s disease may feel well and 

be symptom-free for a long time. They may need 

to take drugs for long periods of time, but most 

are able to hold jobs, raise families, and live 

fulfilling lives. 

12 
Glossary 

anti-inflammatory (AN-tee-in-FLAM-uh-toh-ree): 

preventing or reducing inflammation. 

colectomy (koh-LEK-toh-mee): an operation to
 

remove all or part of the colon.
 

colonoscopy (KOH-lon-OSS-kuh-pee): a test to 

look into the rectum and colon. The doctor uses a 

long, flexible, narrow tube with a light and tiny lens 

on the end. This tube is called a colonoscope. 

fistulas (FISS-tyoo-luhs): an abnormal passage 

between two organs or between an organ and the 

outside of the body. Caused when damaged tissues 

come into contact with each other and join 

together while healing. 

ileum (IL-ee-uhm): the lower end of the small 

intestine. 

sigmoidoscopy (SIG-moy-DOSS-kuh-pee): 

looking into the sigmoid colon and rectum with a 

flexible or rigid tube, called a sigmoidoscope. 

13 
For More Information 

Crohn’s & Colitis Foundation of America 

386 Park Avenue South, 17th Floor
 

New York, NY 10016–8804
 

Phone: 1–800–932–2423 


Email: info@ccfa.org
 

Internet: www.ccfa.org
 

Reach Out for Youth with Ileitis and Colitis, Inc. 

84 Northgate Circle 

Melville, NY 11747 

Phone: 631–293–3102 

Email: reachoutforyouth@reachoutforyouth.org 

Internet: www.reachoutforyouth.org 

United Ostomy Associations of America, Inc. 

P.O. Box 66
 

Fairview, TN 37062
 

Phone: 1–800–826–0826
 

Email: info@uoaa.org
 

Internet: www.uoaa.org
 

14
 
Acknowledgments 

The National Digestive Diseases Information 

Clearinghouse (NDDIC) would like to thank the 

following individual for assisting with the scientific 

and editorial review of this publication: 

Marla Dubinsky, M.D. 


Cedars-Sinai Medical Center
 

Los Angeles, CA
 

Thanks also to Jyl Pomeroy, B.S., R.N., at the 

Arlington Free Clinic, Arlington, VA, for 

facilitating field-testing of this publication. 

The U.S. Government does not endorse or favor any specific 

commercial product or company. Trade, proprietary, or company 

names appearing in this document are used only because they are 

considered necessary in the context of the information provided. 

If a product is not mentioned, the omission does not mean or imply 

that the product is unsatisfactory. 

15 

National Digestive Diseases 

Information Clearinghouse 

2 Information Way 

Bethesda, MD 20892–3570 

Phone: 1–800–891–5389 

Fax: 703–738–4929 

Email: nddic@info.niddk.nih.gov 

Internet: www.digestive.niddk.nih.gov 

The National Digestive Diseases Information Clearinghouse 

(NDDIC) is a service of the National Institute of Diabetes 

and Digestive and Kidney Diseases (NIDDK). The NIDDK 

is part of the National Institutes of Health of the U.S. 

Department of Health and Human Services. Established 

in 1980, the Clearinghouse provides information about 

digestive diseases to people with digestive disorders and to 

their families, health care professionals, and the public. 

The NDDIC answers inquiries, develops and distributes 

publications, and works closely with professional and patient 

organizations and Government agencies to coordinate 

resources about digestive diseases. 

Publications produced by the Clearinghouse are carefully 

reviewed by both NIDDK scientists and outside experts. 

This publication is not copyrighted. The Clearinghouse 

encourages users of this booklet to duplicate and 

distribute as many copies as desired. 

This booklet is also available at www.digestive.niddk.nih.gov. 
U.S. DEPARTMENT OF HEALTH 

AND HUMAN SERVICES 

National Institutes of Health 

National Institute of Diabetes and 

Digestive and Kidney Diseases 

NIH Publication No. 07–5774 

May 2007