What Is Crohn's Colitis?

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Crohn's colitis is a type of Crohn's disease, a form of inflammatory bowel disease (IBD). Several types of Crohn's exist, and each one is distinguished by the part of the digestive tract it affects. With Crohn's colitis, the colon (large intestine) is inflamed.

Sometimes called granulomatous colitis, this condition accounts for 20% of all Crohn's diagnoses. You can have Crohn's colitis only or more than one type of Crohn's at the same time. Despite having a similar name, this condition is not the same as ulcerative colitis.

This article looks at the symptoms of Crohn's colitis, its causes, and how it's diagnosed and treated.

Medical professional displaying model of large intestine
ericsphotography / E+ / Getty Images

Understanding Colitis

Colitis is a general term that means inflammation in the large intestine—the tubular organ that connects your small intestine to your anus.

Crohn's disease is just one possible cause of colitis. Some others have nothing to do with IBD.

For instance, colitis can be caused by infection with a parasite, virus, or bacteria. It can also result from ischemia (a lack of blood flow) or occur as a side effect of radiation therapy.

Some of these forms of colitis are acute, meaning they come on suddenly. Infectious colitis often improves with treatment.

But colitis that is caused by IBD, like Crohn's colitis, is considered chronic. While the disease might go into remission or improve with treatment, it's never cured.

Crohn's Colitis vs. Ulcerative Colitis

Crohn's disease and ulcerative colitis are the two main types of IBD. Both can cause colitis.

But Crohn's colitis and ulcerative colitis are distinct condition, and their differences matter when it comes to diagnosis and treatment.

Crohn's Colitis
  • Pockets of inflammation between areas of healthy tissue

  • Cobblestone-like appearance of intestines

  • Inflammation is deep in the colon

Ulcerative Colitis
  • Inflammation is continuous (no healthy tissue)

  • No cobblestone-like appearance of intestines

  • Inflammation is in the shallow layers

Symptoms of Crohn's Colitis

The most common symptoms of Crohn's colitis include:

  • Diarrhea (often bloody)
  • Weight loss
  • Abdominal pain

An abscess, or pocket of pus in the colon, can also occur. This can cause:

  • Severe abdominal pain
  • Painful bowel movements
  • Pus leaking through the anus
  • Fever

A fistula is an abnormal passage between two tube-like organs or between a tube-like organ and the outside of the body. With Crohn's colitis, a fistula can form between the bowel and the bladder, vagina, skin, or another part of the bowel.

Symptoms of fistulas include:

  • Frequent infection
  • Diarrhea
  • Abdominal pain
  • Fever
  • Weight loss
  • Nausea
  • Vomiting

Some of these symptoms commonly occur with other conditions, so they may not immediately be recognized as being due to Crohn's colitis. The similarities among the symptoms of Crohn's colitis-related problems themselves can make them difficult to tell apart as well.

What Causes Crohn's?

Crohn's disease is considered autoimmune, meaning it is part of a group of disorders in which the immune system mistakenly identifies a healthy cell, tissue, or substance in your body as dangerous. It then creates specialized cells called antibodies to attack and destroy it.

Researchers don't yet understand why autoimmune diseases develop. Experts believe a combination of genetics and environmental factors lead to Crohn's colitis and other forms of Crohn's disease. These factors include:

  • Smoking
  • Taking antibiotics
  • Frequent use of non-steroidal anti-inflammatory drugs (NSAIDs) such as Advil (ibuprofen) and Aleve (naproxen)
  • Birth control pill use

Crohn's colitis is most common in North America, Western Europe, and in people with Eastern European backgrounds. Rates are increasing among Black people in the U.S., as well as in Asian and South American countries.


It can be difficult to tell Crohn's colitis apart from ulcerative colitis and other similar conditions. Healthcare providers perform a physical exam plus a range of tests, including:

  • Colonoscopy: A long, flexible tube with a camera and light on it are threaded into the large intestine through the anus. Small bits of tissue may be removed (biopsied) for examined.
  • Upper endoscopy: A similar scope is inserted through the mouth and down into the stomach and part of the small intestine. More biopsies are taken.
  • Capsule endoscopy: You swallow a pill-sized camera and wear a device that records the images as the camera travels through the small intestine.
  • Abdominal computed tomography (CT) scans: Images show a cross-sectional view of the bowel and can reveal bleeding, obstructions, and other signs of Crohn's.
  • Blood tests: A lab checks red and white blood cell count and inflammatory markers including C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR or sed rate).
  • Stool tests: The lab checks samples for blood, bacterial infection, and parasites.

Being diagnosed with Crohn's colitis doesn't mean Crohn's will never affect the small intestine or other areas of your digestive tract. It just means it's not present there right now.

Changes in Your Diagnosis

If the disease goes on to affect other parts of the digestive tract, then your diagnosis will change.

For example, if it's discovered that the ileum (small intestine) is involved in addition to the colon, you will be diagnosed with ileocolitis—one of the four other forms of Crohn's.

If other areas are affected, you may be diagnosed with Crohn's colitis and an additional type. Possibilities include:

  • Gastroduodenal Crohn's disease: Involves the esophagus, stomach, and/or upper part of the small intestine
  • Jejunoileitis: Involves approximately half of the upper portion of the small intestine

(The fifth type of Crohn's, ileitis, only affects the ileum.)

If Crohn's affects many regions throughout the digestive tract, it might not neatly fall into one of the classifications.


Identifying Crohn's colitis helps guide medical and surgical management. Diet also plays an important role in reducing flares.


Medications used for Crohn's include:

  • Corticosteroids and aminosalicylates: Drugs that can help control inflammation
  • Immunomodulators: Drugs that reduce autoimmune activity
  • Biologics: Drugs that alter your immune response
  • Antibiotics: Drugs to treat bacterial infections, as needed


Diet is an important part of managing Crohn's colitis. No single diet works for everyone, though. You'll need to do some experimenting to figure out what's best for you.

Still, some practices are often helpful and provide you with a place to start. They include:

  • Eating between four and six small meals a day
  • Staying hydrated
  • Drinking slowly
  • Not drinking through a straw, which can make you swallow air and become gassy
  • Keeping your kitchen stocked with food you know you can tolerate
  • Preparing meals in advance so you have something safe to eat even when you're not up to cooking

You may want to use a food journal to help figure out what foods do or don't bother you. Some types of foods (e.g., fruit with seeds and skins, dairy) tend to be problematic for people with Crohn's colitis. Others (e.g., fish, refined grains) tend to be "safe."

Because you may need to avoid some types of healthy food, you may need to take nutritional supplements. Your healthcare provider or a dietitian can help you decide what nutrients may be lacking in your diet.

Surgery for Complications

In some cases, surgery may be needed because of complications such as:

  • Bowel obstruction
  • Abscess
  • Fistula
  • Excessive bleeding
  • Intestinal rupture (when a hole develops in the wall of the digestive tract)
  • Toxic megacolon (when inflammation spreads into the deeper layers of the colon and cause it to stop working)

Ask your doctor about how you may be able to manage symptoms with your diet and nutritional supplements, as well.


Crohn's colitis is a form of Crohn's disease that specifically causes inflammation in the large intestine. It leads to bloody diarrhea, weight loss, and abdominal pain, and may cause complications such as abscesses and fistulae.

It is diagnosed with a colonoscopy, upper endoscopy, other scans, and blood and stool tests. But if Crohn's begins to affect areas in the digestive tract beyond the colon, that diagnosis will change.

Diet and medication are typically enough to manage uncomplicated cases. Complications may require surgery.

A Word From Verywell

If you have intestinal symptoms that could be Crohn's colitis, see your doctor right away. You may need a referral to a gastroenterologist—a doctor who specializes in diseases of the gastrointestinal system—for diagnosis and management.

The sooner you get that process started, the sooner you'll start feeling better.

9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Crohn's & Colitis Foundation. Abscess drainage.

  3. University of California Los Angeles: UCLA Health. Fistulas.

  4. Crohn's & Colitis Foundation. Causes of Crohn's disease.

  5. Feuerstein JD, Cheifetz AS. Crohn disease: Epidemiology, diagnosis, and management. Mayo Clin Proc. 2017;92(7):1088-1103. doi:10.1016/j.mayocp.2017.04.010

  6. National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases. Diagnosis of Crohn's disease.

  7. Cheifetz AS. Management of active Crohn diseaseJAMA. 2013;309(20):2150–2158. doi:10.1001/jama.2013.4466

  8. Zenlea T, Peppercorn MA. Immunosuppressive therapies for inflammatory bowel disease. World J Gastroenterol. 2014;20(12):3146-52. doi:10.3748/wjg.v20.i12.3146

  9. Crohn's & Colitis Foundation. What should I eat?

Additional Reading

By Amber J. Tresca
Amber J. Tresca is a freelance writer and speaker who covers digestive conditions, including IBD. She was diagnosed with ulcerative colitis at age 16.