What is Crohn’s disease?
Crohn’s disease, also called regional enteritis or ileitis, is a lifelong form of inflammatory bowel disease (IBD). The condition inflames and irritates the digestive tract — specifically the small and large intestines. Crohn’s disease can cause diarrhea and stomach cramps. It’s common to experience periodic disease flare-ups.
Crohn’s disease gets its name from American gastroenterologist Dr. Burrill Crohn (1884-1983). He was one of the first physicians to describe the illness in 1932. Ulcerative colitis is another commonly diagnosed IBD.
How common is Crohn’s disease?
An estimated half a million Americans have Crohn’s disease. This can include men, women and children.
Who might get Crohn’s disease?
Crohn’s disease typically appears in younger people – often in their late teens, 20s or early 30s. However, this condition can happen at any age. It’s equally common in men and women. Crohn’s disease can also be see in young children.
If you’re a cigarette smoker, your risk of Crohn’s disease might be higher than non-smokers.
What are the types of Crohn’s disease?
Crohn’s disease can affect different sections of the digestive tract. Types of Crohn’s disease include:
- Ileocolitis: Inflammation occurs in the small intestine and part of the large intestine, or colon. Ileocolitis is the most common type of Crohn’s disease.
- Ileitis: Swelling and inflammation develop in the small intestine (ileum).
- Gastroduodenal: Inflammation and irritation affect the stomach and the top of the small intestine (the duodenum).
- Jejunoileitis: Patchy areas of inflammation develop in the upper half of the small intestine (called the jejunum).
Symptoms and Causes
What causes Crohn’s disease?
There’s no known cause of Crohn’s disease. Certain factors may increase your risk of developing the condition, including:
- Autoimmune disease: Bacteria in the digestive tract may cause the body’s immune system to attack your healthy cells.
- Genes: Inflammatory bowel disease (IBD) often runs in families. If you have a parent, sibling or other family member with Crohn’s, you may be at an increased risk of also having it. There are several specific mutations (changes) to your genes that can predispose people to developing Crohn’s disease.
- Smoking: Cigarette smoking could as much as double your risk of Crohn’s disease.
What are the symptoms of Crohn’s disease?
People with Crohn’s disease can experience periods of severe symptoms (flare-ups) followed by periods of no or very mild symptoms (remission). Remission can last weeks or even years. There’s no way to predict when flare-ups will happen.
If you have Crohn’s disease, symptoms you might have can include:
- Abdominal pain.
- Chronic diarrhea.
- A feeling of fullness.
- A loss of your appetite.
- Weight loss.
- Abnormal skin tags (usually on your buttocks).
- Anal fissures.
- Anal fistulas.
- Rectal bleeding.
Diagnosis and Tests
How is Crohn's disease diagnosed?
Most people with Crohn’s first see a healthcare provider because of ongoing diarrhea, belly cramping or unexplained weight loss. If you have a child who has been experiencing the symptoms of Crohn’s disease, reach out to your pediatrician.
To find the cause of your symptoms, your healthcare provider may order one or more of these tests:
- Blood test: A blood test checks for high numbers of white blood cells that may indicate inflammation or infection. The test also checks for low red blood cell count, or anemia. Approximately one in three people with Crohn’s disease have anemia.
- Stool test: This test looks at a sample of your stool to check for bacteria or parasites. It can rule out infections that cause chronic diarrhea.
- Colonoscopy: During a colonoscopy, your doctor uses an endoscope (thin tube with an attached light and camera) to examine the inside of your colon. Your doctor may take a tissue sample (biopsy) from the colon to test for signs of inflammation.
- Computed tomography (CT) scan: A CT scan creates images of the digestive tract. It tells your healthcare provider how severe the intestinal inflammation is.
- Upper gastrointestinal (GI) endoscopy: Your doctor threads a long, thin tube called an endoscope through your mouth and into your throat. An attached camera allows your doctor to see inside. During an upper endoscopy, your doctor may also take tissue samples.
- Upper gastrointestinal (GI) exam: X-ray images used during an upper GI exam allow your doctor to watch as a swallowed barium liquid moves through your digestive tract.
Management and Treatment
How is Crohn’s disease managed or treated?
Treatment for Crohn’s disease varies depending on what’s causing your symptoms and how severe they are for you. In children, the goal in treatment is to induce remission (the time between symptom flare-ups), maintain remission and manage any complications of Crohn’s disease over time.
Your healthcare provider may recommend one or more of these treatments for Crohn's disease:
- Antibiotics: Antibiotics can prevent or treat infections. Severe infections can lead to abscesses (pockets of pus). Or they can cause fistulas (openings or tunnels that connect two organs that don’t normally connect).
- Antidiarrheal medication: Prescription medications like loperamide (Imodium A-D®) can stop severe diarrhea.
- Biologics: These medications include monoclonal antibodies to suppress the immune response.
- Bowel rest: To give your intestines a chance to heal, your provider may recommend going without food or drink for several days or longer. To get the nutrition you need, you may receive intravenous (parenteral) nutrition. Only drink a prescribed liquid or have a feeding tube during this time.
- Corticosteroids: Cortisone, prednisone and other corticosteroids ease inflammation brought on by autoimmune disease.
- Immunomodulators: These drugs calm inflammation by suppressing an overactive immune system. They include azathioprine and cyclosporine.
- Surgery: Surgery won’t cure Crohn’s disease, but it can treat complications. You may need surgery to correct intestinal perforations (holes), blockages or bleeding.
What are the complications of Crohn’s disease?
Crohn’s disease can lead to serious complications, including:
- Abscesses: Infected pus-filled pockets form in the digestive tract or abdomen.
- Anal fissures: Small tears in the anus (anal fissures) can cause pain, itching and bleeding.
- Bowel obstructions: Scar tissue from inflammation, fistulas or a narrowed intestine can block the bowel partially or completely. Waste matter and gases build up. A blockage in the small bowel or large bowel requires surgery.
- Colon cancer: Crohn’s disease in the large intestine increases the risk of colon cancer.
- Fistulas: IBD can cause abnormal tunnel-like openings, called fistulas, to form in the intestinal walls. These fistulas sometimes become infected.
- Malnutrition: Chronic diarrhea can make it hard for your body to absorb nutrients. One common problem in people with Crohn’s disease is a lack of iron. Too little iron can lead to anemia (low red blood cell count) when your organs can’t get enough oxygen.
- Ulcers: Open sores called ulcers can form in your mouth, stomach or rectum.
How does Crohn’s disease affect pregnancy?
Women with Crohn’s disease can, and usually do, have normal pregnancies. Your healthcare provider may recommend trying to conceive while the disease is in remission. Flare-ups during pregnancy may increase the risk of:
- Miscarriage (loss of pregnancy before the baby fully develops).
- Premature labor (childbirth before the 37th week of pregnancy).
- Low birth weight (newborn weight of less than 5 pounds, 8 ounces).
How can I prevent Crohn’s disease?
There’s no way to prevent Crohn’s disease. These healthy lifestyle changes can ease symptoms and reduce flare-ups:
- Stop smoking.
- Eat a healthy, low-fat diet.
- Exercise regularly.
- Manage stress.
Outlook / Prognosis
What is the prognosis (outlook) for people with Crohn’s disease?
Most people with Crohn’s disease enjoy healthy, active lives. While there isn’t a cure for Crohn’s disease, treatments and lifestyle changes can keep the disease in remission and prevent complications.
Lifestyle changes can include changes to your diet. People with Crohn’s disease often need to adapt their diets so that they get enough calories each day. Lactose intolerance can also be an issue for those with Crohn’s disease. You may need to avoid certain dairy products if you find that you’re having issues with this dietary intolerance. You should also avoid smoking if you have Crohn’s disease. Smoking can only make your condition worse.
Your healthcare provider might recommend you receive preventative colonoscopies after you’re diagnosed with Crohn’s disease. Talk to your provider about how often you should have colonoscopies and what your risks are for other medical conditions.
When should I call the doctor?
You should call your healthcare provider if you experience:
- Blood in stool.
- Extreme weight loss.
- Inability to pass gas.
- Nausea and vomiting.
- Severe abdominal pain.
- Signs of a flare-up.
- Uncontrollable diarrhea.
- Weakness or fatigue that may be signs of anemia.
What questions should I ask my doctor?
If you have Crohn’s disease, you may want to ask your healthcare provider:
- Why did I get Crohn’s disease?
- What form of Crohn’s disease do I have?
- What’s the best treatment for this disease type?
- How can I prevent flare-ups?
- If I have a genetic form, what steps can my family members take to lower their risk of Crohn’s disease?
- Should I make any dietary changes?
- What medications should I avoid?
- Should I take supplements?
- Should I get tested for anemia?
- Do I need to cut out alcohol?
- Should I look out for signs of complications?
A note from Cleveland Clinic
Crohn’s disease flare-ups are unpredictable and can disrupt your daily life. Talk to your healthcare provider about the steps you can take to keep the disease in check. With the right treatment and lifestyle changes, you can manage symptoms, avoid complications and live an active life.
Cleveland Clinic Podcasts
Visit our Butts & Guts Podcasts page to learn more about digestive conditions and treatment options from Cleveland Clinic experts.
Where can I go for more information?
The following organizations can provide more information about Crohn's disease:
Crohn's and Colitis Foundation of America, Inc. IBD help Center.
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