What Is Crohn's Colitis?

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Crohn's colitis is a form of Crohn's disease. Despite the similar names, Crohn's colitis is not the same as ulcerative colitis. They're different types of inflammatory bowel disease (IBD).

Several types of Crohn's disease exist, based on the part of the gastrointestinal system it affects. You can have more than one type. The term "colitis" means primarily affecting the colon (large intestine).

Crohn's colitis is diagnosed when Crohn's disease mainly or only affects the colon. It accounts for a 20% of all Crohn's diagnoses. Sometimes, the condition is called granulomatous colitis.

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

Medical professional displaying model of large intestine
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Crohn's Types

Crohn's disease is often subclassified based on the location of involvement. However, if it affects many regions throughout the digestive tract, it might not fall into one of the classifications.

The five types of Crohn's disease are:

  • Ileocolitis involves the ileum (small intestine) and colon
  • Ileitis involves only the small intestine
  • 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
  • Crohn's colitis

Crohn's colitis is one of the more common forms of Crohn's disease.


Colitis is a general term that means inflammation in the large intestine. Colitis has a variety of causes that have nothing to do with ulcerative colitis or Crohn's disease, or even IBD.

It can be caused by infection with a parasite, virus, or bacteria. Colitis 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.

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

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


The most common symptoms of this form of Crohn's colitis include:

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

It also involves abscesses and fistulae. An abscess is a pocket of pus. When one develops in Crohn's colitis, it 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. It can form between the bowel and the:

  • Bladder
  • Vagina
  • Skin
  • Other part of the bowel

Symptoms of fistulas include:

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

These symptoms are all similar, which means it may be hard to tell these problems apart. If you have a marked change or increase in your symptoms, let your healthcare provider know right away.


Crohn's colitis is different from ulcerative colitis. It's one of the five types of Crohn's, which are based on where the disease activity is in the digestive tract. Crohn's colitis affects the large intestine. Symptoms can include bloody diarrhea, weight loss, abdominal pain, and other possible symptoms due to abscesses or fistulae.


Researchers don't yet understand why autoimmune diseases develop.

The causes of Crohn's colitis, and other forms of Crohn's disease, are thought to be a combination of genetics and environmental factors such as:

  • Smoking
  • Taking antibiotics
  • Frequent use of non-steroidal anti-inflammatory drugs (NSAIDs)
  • The birth control pill

It's 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 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 scope with a light and camera are 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 CT (computed tomography) scans: Images show a cross-sectional view of the bowel and can identify 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 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.

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


Crohn's colitis is believed to be caused by genetics plus environmental factors such as smoking and taking certain medications.

It's diagnosed through a combination of scans and lab tests.


Identifying Crohn's colitis helps guide medical and surgical management. If you have Crohn's disease affecting your large intestine, treatment and follow-up tests will be tailored to your disease.

Medications may include:

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

In some cases, surgery may be needed because of complications such as bowel obstruction, abscess, fistula, excessive bleeding, intestinal rupture, and toxic megacolon.

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. It's not the same as ulcerative colitis. This disease causes inflammation in the large intestine.

About 20% of people with Crohn's disease have this form. Other forms include ileocolitis, Ileitis, gastroduodenal, and jejunoileitis. "Colitis" means inflammation of the colon.

Symptoms include bloody diarrhea, weight loss, and abdominal pain. Possible complications are abscesses and fistulae.

Causes are believed to include genetics and certain environmental factors. Crohn's colitis is diagnosed with a colonoscopy, upper endoscopy, other scans, and blood and stool tests.

It's treated with medications that reduce inflammation and autoimmune activity, plus antibiotics to fight infections when necessary.

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 for diagnosis and management. The sooner you get that process started, the sooner you'll start feeling better.

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8 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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