Eosinophilic Colitis

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Eosinophilic colitis (EC) is a rare disease in which a type of white blood cell, the eosinophil, appears in elevated numbers in the large intestine. This in turn causes injury and inflammation.

When seen in infancy, it is mostly a benign disease, resolving by early childhood once an offending food is eliminated and outgrown. In adolescents and adults, EC is often chronic and recurring.

What causes eosinophilic colitis?

The cause of eosinophilic colitis is unknown in many patients. Cow’s milk protein often exacerbates symptoms. People who have a personal or family history of allergic disorders may be at higher risk of developing eosinophilic colitis.

EC may also occur in conjunction with other eosinophil associated gastrointestinal diseases.

What are the symptoms?

EC in infants is characterized by a bloody diarrhea that comes on suddenly and often wanes over time. If blood loss is significant, anemia can develop. In some, these symptoms can also lead to weight loss, malnourishment, and difficulty feeding; yet many infants have no other symptoms and appear otherwise healthy.

In older patients, common symptoms include diarrhea, abdominal pain, and weight loss. Other symptoms can include fatigue and trouble gaining weight.

Common symptoms list:

  • Bloody diarrhea
  • Anemia (low blood counts)
  • Vomiting, nausea
  • Difficulty feeding and/or gaining weight
  • Poor growth and weight loss
  • Malnutrition
  • Abdominal pain
  • Fatigue

Who is Affected?

Eosinophilic colitis may affect both adults and children, and may affect both males and females. It often presents before 6 months of age.

In infants, ingestion of soy or cow milk proteins through breastfeeding or formulas often exacerbates symptoms. Virtually all cases of this intolerance appear within the first year, and is usually outgrown in the child’s first decade of life. Those with a personal or family history of allergic disorders may be at higher risk of developing eosinophilic colitis.

How is eosinophilic colitis diagnosed?

Eosinophilic colitis is diagnosed by a lower endoscopy (colonoscopy) where a small tube is directed through the anus, rectum, and large intestine. This tube allows the doctor to see any visual changes in the tissue, such as erosions, ulcers, or irritated areas of the large intestine. The doctor will take small tissue samples (biopsies) from each section of the lower GI tract.

The biopsies are examined under a high-powered microscope to see the small cell structures. If eosinophils are present in the sample, the pathologist will count how many are visible. The colon typically has low numbers of eosinophils present, and there are no consensus guidelines to suggest a threshold for what is considered elevated. Therefore, diagnosis is based on clinical symptoms, visual evidence in the endoscopy, the pathology report, and how well the patient responds to therapy.

High levels of eosinophils in the colon may also be caused by other conditions such as helminthic infections (e.g., pin worms, hookworms), inflammatory bowel disease, autoimmune disease, celiac disease, drug reactions, and in association with hypereosinophilic syndrome.

How is eosinophilic colitis treated?

There are no consensus guidelines for the treatment of eosinophilic colitis.
The goal of the treatment is to reduce the inflammation and damage caused by the eosinophils.

With the exception of EC in infancy, the disease is less likely to be allergic in nature than other eosinophil gastrointestinal diseases. However, your doctor may suggest allergy testing to help determine if a specific allergen is triggering EC. Once allergens have been identified or ruled out, there are two main therapies used to manage EC:

Dietary Therapy – Dietary therapy involves removing suspected causative foods; eliminating common food allergens such as milk, wheat, soy, fish, shellfish, peanuts, tree nuts, and eggs; or removing food entirely from the diet and relying on specialized formula for nutrition.

For some patients, especially infants, only a few foods are identified as causing the problem (typically milk and/or soy), and once those foods are removed from the diet, EC resolves.

Steroids– Systemic steroids such as prednisone and/or topical steroids (suppository or enema) may be prescribed. Anti-inflammatory medications for the large intestine may also be used.

To evaluate how you are responding to treatment, periodic endoscopies with biopsies will be performed.

What is the prognosis?

The EC that develops in infancy carries a good prognosis. It tends to spontaneously resolve, often within days. Dietary management has also shown to put EC in remission, especially in the infant population.

For young adults and adults with EC, prognosis depends on the response to treatment. EC is chronic with periods of activity and periods of apparent remission. More aggressive medical management is often necessary, and may include antihistamines, glucocorticoids, and leukotriene receptors antagonists.

Frequently Asked Questions

Q: Are there consensus guidelines for EC?

A: Not at the current time, in part because so few patients have EC. The American Academy of Asthma, Allergy, and Immunology, and the leading gastroenterology groups, have created a bi-annual symposium on

eosinophilic digestive disorders, which may lead to future clinical treatment guidelines and management. (For more information about The International Gastrointestinal Eosinophil Researchers:

The value of the consensus statement on eosinophilic esophagitis is that it came from existing medical literature rather than just opinion.

Comparable data for EC does not exist, and most literature is limited to case studies (very small numbers). Research is being done, but it is difficult to get enough patients. Given the apparent increase in cases noted around the country by many physicians, it is likely that more research findings will develop in the next few years.

Q: Can the treatment info on EoE be applied to ECS?

A: The global approach to treating all eosinophil-associated gastrointestinal disease (EGID) is to reduce inflammation. The principles of treatment are the same between EGID subsets. Continued monitoring for development of inflammatory bowel diseases should always be considered since some treatments for eosinophilic gastroenteritis can also mask the development of inflammatory bowel diseases, such as ulcerative colitis or Crohn’s.

Q: Should I be concerned about scarring from repeated scopes and biopsies?

A: The risk of scarring from endoscopy itself is virtually zero. The scope itself does not cause trauma under normal circumstances, and the size of the biopsies are very small. There is a small risk associated with repeated anesthesia; and there is always risk with any procedure.

Q: Are EGIDs deadly?

A: EGIDs are generally not immediately life threatening, though they have a significant impact on quality of life. Complications from EGIDs can develop that may become deadly without intervention, such as severe malnutrition, dehydration, or food impaction due to structural changes in the esophagus. These issues are more likely to have significant impacts on infants and young children unlike teens/adults who can describe difficulties more easily.

Other Resources



Lozinsky A., Morais M. “Eosinophilic colitis in infants.” J Pediatr (Rio J). 2013

Alfadda A., Storr M, Shaffer E. “Eosinophilic colitis: an update on pathophysiology and treatment.” Br Med Bull (2011) 100 (1): 59-72.doi: 10.1093/bmb/ldr045

Alfadda A., Storr M, Shaffer E.” Eosinophilic colitis: epidemiology, clinical features, and current management” Therap Adv Gastroenterol. Sep 2011; 4(5): 301–309. doi: 10.1177/1756283X10392443

© American Partnership for Eosinophilic Disorders (APFED) 2004-2016 All rights reserved. Content may not be reproduced in whole or in part without express written consent from APFED. Contact us at Contributors: Wendy Book, MD; Harvey Leo, MD; Mary Jo Strobel; Kelly Morris