Crohn’s Disease: Symptoms, Causes & Treatment

Crohn’s Disease: Symptoms, Causes & Treatment

Crohn’s disease is a type of inflammatory bowel disease (IBD) that causes your digestive tract to become swollen and irritated. If you have Crohn’s, you might experience symptoms like abdominal pain, diarrhea, weight loss and rectal bleeding. This is a lifelong condition that can’t be cured. However, treatments typically help manage your symptoms and allow you to live an active life.

What is Crohn’s disease?

Crohn’s disease is a chronic (lifelong) autoimmune condition that inflames and irritates your digestive tract, most commonly your small and large intestines (colon). Crohn’s disease and ulcerative colitis are the two most common forms of inflammatory bowel disease (IBD).

Crohn’s disease may cause unpleasant symptoms, most commonly diarrhea and stomach cramps or abdominal pain.

What are the types of Crohn’s disease?

Crohn’s disease can affect any part of your digestive tract, from your mouth to your anus (butthole). Most commonly, it causes inflammation in your small and/or large intestines. Types of Crohn’s disease include:

  • Ileocolitis: Inflammation in your lower small intestine and part of your large intestine. Ileocolitis is the most common type of Crohn’s disease.
  • Colitis: Inflammation in the lining of your large intestine.
  • Ileitis: Swelling and inflammation in your small intestine (ileum).
  • Gastroduodenal: Inflammation and irritation that affects your stomach and the top of your small intestine (the duodenum).
  • Jejunitis: Patchy areas of inflammation in the upper half of your small intestine (the jejunum).
  • Perianal disease: A portion of people have inflammation around the anus, which can cause fistulas and abscesses.

How common is Crohn’s disease?

Experts estimate that more than three-quarters of a million people in the U.S. have Crohn’s disease. It affects approximately 6 to 8 million people globally.

Symptoms and Causes

What are the signs and symptoms of Crohn’s disease?

Symptoms may develop gradually or come on suddenly. They may be mild to severe. Some people have chronic symptoms until a provider successfully treats them, while others have symptoms that come and go. A “flare” is when symptoms are active.

Common Crohn’s disease signs and symptoms include:

  • Abdominal pain or cramps.
  • Chronic diarrhea (watery stool).
  • Loss of appetite and weight loss.
  • Bloody stool (rectal bleeding).
  • Mouth ulcers or pain in your mouth or gums.
  • Fever and fatigue (tiredness that doesn’t improve with rest).
  • Abscesses of infections around your anal canal.

Crohn’s can also cause symptoms in body parts outside of your digestive tract, including:

  • Arthritis or joint pain.
  • Rashes.
  • Eye inflammation, such as uveitis and episcleritis.
  • Kidney stones.
  • Osteoporosis (loss of bone mass).
  • Skin tags (usually around your anus).
  • Inflammation in your bile ducts.

Crohn’s disease in children can cause growth delays or failure to grow properly.

What are the complications of Crohn’s disease?

Crohn’s disease can cause complications that may require more treatment or, possibly, surgery.

  • Abscesses: Infected pus-filled pockets that form in your digestive tract or abdomen.
  • Anal fissures: Small tears in your anus that cause pain, itching and bleeding.
  • Fistulas: An abnormal tunnel-like opening that connects two body parts that don’t normally connect. For example, with Crohn’s disease, fistulas sometimes cause an opening between your rectum or anal canal inside your body and the skin surrounding your anus outside your body (anal fistula).
  • Bowel obstructions: A partial or total blockage in your intestine. Obstructions can develop when scar tissue forms or abnormal narrowing called strictures occur.
  • Malnutrition: Not getting the proper amount of nutrients. Inflammation can make it hard for your body to absorb key nutrients. Symptoms can make it difficult to consume the foods you need for energy.
  • Anemia: Low blood cell counts. Approximately 1 in 3 people with Crohn’s disease have anemia.

Crohn’s disease can also increase your risk of colon cancer and blood clots.

What causes Crohn’s disease?

There’s no known single cause of Crohn’s disease, but it’s related to a dysfunctional immune response.

Usually, your immune system switches into attack mode to destroy germs that enter your body. Inflammation is a sign that your body’s fighting the germs. Once the threat is gone, your immune system calms and the inflammation disappears.

An autoimmune response happens when your immune system launches into overdrive and attacks your body’s own cells. For example, your immune system may launch an inappropriate attack on bacteria normally found in your gut, causing Crohn’s-related inflammation in your intestines.

Crohn’s sometimes runs in families. It’s possible that whatever causes your body’s immune system to attack your body’s healthy cells is hereditary (inherited). Still, many people with Crohn’s have no family history.

What are the risk factors of Crohn’s disease?

Risk factors include:

  • Age: You can get Crohn’s disease at any age, but a large percentage of people are diagnosed in their late teens through early 30s.
  • Genes: Inflammatory bowel disease (IBD) runs in families in about 20% of Crohn’s disease diagnoses. If you have a biological parent, sibling or another family member with Crohn’s, you may be at an increased risk of also having it. Several specific mutations (changes) to your genes can predispose people to developing Crohn’s disease.
  • Smoking: Smoking cigarettes increases your risk of Crohn’s disease. Studies have found that it doubles your risk. It also leads to more severe disease.
  • Appendectomy: Studies suggest that people who have had an appendix surgery may have an increased risk of Crohn’s. The reasons are unclear, but you still shouldn’t avoid this life-saving surgery if you need it.
  • Location: People living in developed countries and urban areas have a higher risk than those living in less developed countries and rural areas.
  • Stress: Your body’s stress response may contribute to flares.

Diagnosis and Tests

How is Crohn’s disease diagnosed?

Most people diagnosed with Crohn’s first see a healthcare provider because of ongoing diarrhea, belly cramping or unexplained weight loss. As part of your workup, you may need to see a doctor who specializes in digestive diseases, called a gastroenterologist.

Your provider will consider your medical history (including your symptoms) and family history. They’ll perform a physical exam to see if you have signs of Crohn’s like swelling or tenderness in your belly. They may perform a series of tests to rule out other conditions before making a diagnosis.

Lab tests

Lab tests check a sample of fluid or tissue for microscopic signs of disease.

  • Blood test: A blood test checks your blood cell counts and blood chemistry for signs of Crohn’s. A high white blood cell count may indicate inflammation or infection. Low levels of red blood cells indicate anemia, common with Crohn’s disease. A protein your liver makes called the C-reactive protein (CRP) may be elevated if there’s active inflammation.
  • Stool test: This test checks a stool (poop) sample for bacteria or parasites. It can rule out infections that cause chronic diarrhea. For example, a calprotectin fecal test measures inflammation in your intestines.

Imaging procedures

Your provider may order imaging tests to take pictures of your digestive tract, such as:

  • Computed tomography (CT) scan: A CT scan creates images of your digestive tract using X-rays. It tells your healthcare provider how severe the inflammation is. You may need a CT enterography, which involves drinking a solution that highlights your small intestine so it stands out more in the images.
  • Magnetic resonance imaging (MRI): An MRI uses a large magnet and radio waves to create images of the inside of your body. It’s especially useful in showing fistulas around your small intestine and anus. You may need to drink a special contrast fluid before the procedure to clarify the images (MRI enterography).


An endoscopy sends a thin tube with a light and camera (endoscope) into your digestive tract to take images or show videos of areas with inflammation. You’ll be sedated for these procedures.

  • Colonoscopy: During this procedure, a provider uses an endoscope to examine the inside of your colon and lower small bowel (ileum). They may remove a tissue sample (biopsy) to test for white blood cells.
  • Upper endoscopy: A provider passes an endoscope through your mouth and into your throat. An attached camera allows your provider to see inside, from your mouth to the start of your small intestine.
  • Capsule endoscopy: You swallow a small plastic capsule with a light and a camera that takes pictures as it moves through your digestive tract.

Management and Treatment

How is Crohn’s disease treated?

There’s currently no cure for Crohn’s disease. There are a variety of therapies but none that work for everyone.

Your healthcare provider will work with you to find the right treatment so that living with Crohn’s is more manageable.


Treatment for Crohn’s disease includes medicines that reduce inflammation and calm your immune response. Studies suggest that treating the inflammation likely improves the long-term outcomes of Crohn’s disease. You may also need treatments to manage specific symptoms, like pain and diarrhea.

  • Steroids: Corticosteroids and budesonide calm inflammation in the short term but are rarely appropriate for long-term symptom management.
  • Anti-inflammatory medications: 5-aminosalicylates are anti-inflammatory medicines used mainly for ulcerative colitis. They provide limited benefits for people with Crohn’s.
  • Immunomodulators: Immunomodulators work by changing how your immune system works. Types called immunosuppressants calm your immune response. Examples include azathioprine and methotrexate.
  • Biologics: Biologics target proteins that cause your immune system to have an excessively activated immune response. There’s a wide range of biologics that you receive either through an IV or a shot. Options include TNF inhibitors, integrin inhibitors, Il-12/23 inhibitors and Il-23 inhibitors.
  • Small molecule advanced therapies: Pills called JAK-inhibitors also reduce the immune response and treat Crohn’s. Upadacitinib (Rinvoq®) is the only one currently approved by the U.S. Federal Drug Administration (FDA).
  • Antibiotics: Antibiotics can treat complications of Crohn’s. Severe infections can lead to abscesses or fistulas.
  • Antidiarrhea medication: Prescription medications like loperamide (Imodium A-D®) can stop severe diarrhea.
  • Pain: There are several therapies used to help with pain related to Crohn’s disease.

All medicines have risks and benefits. Your provider will work with you to choose the medications most likely to help you. They’ll follow up with you to ensure your medications are working.

If your medication isn’t helping or causes unpleasant side effects, contact your healthcare provider.


Getting the right nutrition can improve your health and sometimes treat the disease in the short term. If you’re unable to get the nutrition you need, you may need to receive formula through a feeding tube (enteral nutrition). Depending on the state of your disease, your provider will often offer specific recommendations and do tests to ensure your nutritional needs are met.


Surgery can treat complications of Crohn’s disease. You may need surgery to remove intestinal perforations (holes), fistulas, strictures and blockages.


How can I prevent Crohn’s disease?

You can’t prevent Crohn’s disease, but you can ease symptoms and reduce flare-ups by:

  • Stopping smoking. Quitting smoking is the best thing you can do to reduce your risk of flare-ups and complications.
  • Avoiding medications that can trigger flare-ups. Taking certain medicines can increase your risk of flare-ups. These include some types of NSAIDs (nonsteroidal anti-inflammatory drugs). Ask your healthcare provider what medicines to avoid if you have Crohn’s.
  • Avoiding foods that may trigger unwanted symptoms. There isn’t a single food that triggers inflammation. Still, some foods may make you more likely to have symptoms. Lactose intolerance can be an issue for some. If this is the case, you may need to avoid dairy. You may need to avoid carbonated beverages. If you have a stricture, your provider may advise you to avoid fiber. It’s a good idea to keep a food diary to know which foods are gentle on your stomach and which ones aren’t.
  • Eating foods that work for you with meals spread out. Eating several small meals instead of fewer large ones can reduce your risk of symptoms. When you eat, choose low-fat foods and drink plenty of water. You may benefit from avoiding caffeine and alcohol. Talk to your provider about a meal plan that’s healthy for you.
  • Caring for your mental health. Getting enough rest and exercising regularly improve your overall well-being, which makes life with Crohn’s more manageable. Caring for your mental health is especially important. Stress and anxiety are normal responses to this diagnosis. Seeing a mental health provider can help.

Outlook / Prognosis

Is there a cure for Crohn’s disease?

There isn’t a cure for Crohn’s disease. Once you’re diagnosed, you’ll work closely with your healthcare provider to treat the disease, manage symptoms and prevent complications. Treatment can promote your long-term health.

What is the prognosis (outlook) for people with Crohn’s disease?

Most people with Crohn’s disease enjoy full, active lives. Treatments and lifestyle changes can keep the disease in remission (no signs or symptoms of the disease) and prevent complications. Most people with Crohn’s benefit from ongoing medical therapy and visits.

Your healthcare provider might recommend you receive preventive colonoscopies after you’re diagnosed with Crohn’s disease. Talk to your provider about how often you should have colonoscopies, as well as your risks for other medical conditions. You’ll likely need regular tests to monitor your health depending on the type of Crohn’s you have.

What is the life expectancy of a person with Crohn’s disease?

Crohn’s disease isn’t fatal, and people with Crohn’s disease can live just as long as people without it. Still, managing your condition to prevent complications is important since Crohn’s can increase your risk of certain conditions. For example, regular colonoscopies can catch colon cancer early when it’s treatable.

How does Crohn’s disease affect pregnancy?

Many people with Crohn’s disease have healthy pregnancies. Your healthcare provider may recommend trying to conceive while the disease is in remission and coordinating with a treatment team including your Crohn’s provider and obstetrics team.

Flare-ups during pregnancy may increase your risk of:

  • Miscarriage (loss of pregnancy before week 20).
  • Premature labor (childbirth before the 37th week of pregnancy).
  • Low birth weight (newborn weight of less than 5 pounds, 8 ounces).

Living With

When should I call my provider?

You should call your healthcare provider if you experience:

  • Blood in your stool.
  • Constipation.
  • Extreme weight loss.
  • Fever.
  • Inability to pass gas.
  • Nausea and vomiting.
  • Severe abdominal pain.
  • Signs of a flare-up.
  • Uncontrollable diarrhea.
  • Weakness or fatigue (which may be signs of anemia).

What questions should I ask my provider?

If you have Crohn’s disease, you may want to ask your healthcare provider:

  • What form of Crohn’s disease do I have?
  • What’s the best treatment?
  • How can I prevent flare-ups?
  • Should I make any dietary changes?
  • What medications should I avoid?
  • Can my family members take steps to lower their risk of Crohn’s disease?


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