Eosinophilic colitis (EC) is the buildup of white blood cells called eosinophils in the large intestine. EC can lead to inflammation, tissue damage, ulcers, and polyps.

There are 2 types of EC:

  • Primary—EC that occurs on its own and not because of another disease
  • Secondary—EC that is present because of another disease

EC in infants will go away on its own with time. Adolescent EC may happen in periods without symptoms and periods when symptoms are severe.


It is not clear what causes EC. It is likely a blend of genetics and the environment.

Eosinophils are part of the immune system response to problems in the body. Part of their normal function is to release a chemical that causes inflammation. With EC, eosinophils build up and lead to regular irritation and damage to tissue in the large intestine over time. It is not clear what causes the buildup. It may be a response to an allergen.

Risk Factors

EC is more common in males. Other factors that may increase your child’s chances of EC include:

  • Certain genetic problems
  • Family members with EC or allergies
  • Food allergies
  • Having other conditions, such as other eosinophilic gastrointestinal diseases


Symptoms vary and may be more severe in some people.

Common symptoms include:

  • Severe abdominal pain
  • Diarrhea, with or without blood
  • Nausea
  • Vomiting
  • Fatigue
  • Problems feeding in infants

Complications may include:

  • Malnutrition
  • Weight loss
  • Anemia or iron deficiency from blood loss


You will be asked about your child’s symptoms and medical history. A physical exam will be done. EC is hard to diagnose with simple tests. However, some tests may be able to rule out other diseases with similar symptoms.

Tests to rule other other conditions may include:

  • Blood tests
  • Allergy tests
  • Stool tests
  • Barium enema—a type of x-ray that uses contrast material to highlight the colon
  • Colonoscopy—a lighted tube with a camera is used to view the lining of the colon

A biopsy is the only way to confirm EC. During a biopsy, tissue samples from a colonoscopy are examined under a microscope to confirm a diagnosis


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EC in infants will go away on its own. Removing cow’s milk and soy from the diet might manage symptoms until EC is gone.

For recurring EC, the goal of treatment is to manage inflammation and reduce damage to the lining of the colon. If an underlying cause is identified, it will need to be treated.

Treatment options may include:

Foods that cause symptoms will need to be avoided. Proteins, such as soy, nuts, eggs, or milk are common allergens. A dietitian can help to guide dietary needs.

Other changes may include:

  • If all proteins need to be removed, then only the building blocks of called amino acids can be consumed. Liquid formulas may be needed. In some cases, a feeding tube may be used.
  • A nutritional support program may be needed to support growth. This may include vitamins and supplements.

Medications are used to manage EC and treat complications. These may include:

  • Oral steroids to reduce inflammation during symptom flare ups. Topical steroids, such as suppositories or enemas, can also be used.
  • Medications to boost, change, or suppress the effects of the immune system.
  • Iron pills to treat anemia.


There are no current guidelines to prevent EC because the cause is unknown.