For a while, mealtime for Ashley Zundel, 9, consisted solely of turkey, rice, rice milk, potatoes and apple juice — a shrinking menu that eliminated peanuts, milk, eggs, soy, corn, then sunflower seeds and pizza and celery.

Recently, she had to give up those five foods. She now relies on a feeding tube for nutrition.

The problem is eosinophilic gastroenteritis, which affects her stomach, intestine and colon, according to her parents, Dallyn and Tammy Zundel, of Orem.

Eosinophils are the smallest group of white blood cells, important for their battle against parasites in particular. They are named after the Greek god of dawn, Eos, because they turn bright pink-red when stained for viewing with a microscope.

In people with eosinophilic disorders, the number of the cells greatly increases, causing inflammation and related problems. Many of them also have asthma or eczema, although Ashley has neither.

Her brother, Preston, 7, has a milder form that affects only his colon, called eosinophilic colitis. He also has asthma.

There are a number of eosinophil-associated gastrointestinal disorders, according to the American Partnership for Eosinophilic Disorders (www.apfed.org). What you have depends on where the eosinophils are elevated. And true diagnosis can only be made by endoscopy and biopsy.

Dr. Gerald Gleich, a professor of dermatology and medicine at the University of Utah and a self-described "eosinophilomaniac" with more than 600 articles published on the topic, describes symptoms that include nausea, vomiting, abdominal pain, urgency to go to the bathroom and more. As it goes along, the intestine can "be afflicted to the point where it begins to leak protein. Ordinarily, the intestine is a one-way street, absorbing things."

The prolonged inflammation leads to less effective absorption and protein leakage. The most common treatment, once the diagnosis is confirmed by elevation in the number of blood eosinophils, is corticosteroids, which can "stop it in its tracks. In the short run, it's wonderful. But unless you understand what's going on, the short run becomes the long run," Gleich says. Long-term steroid use brings a "passel of difficulties," including cataracts, thinning of bones and skin, high blood pressure, weight gain and more.

Food-allergy tests help guide treatments, and certain foods may be eliminated. Doctors sometimes prescribe an "elemental diet," with no proteins or complex carbohydrates. An elemental diet has, instead, monosaccharides, very simple fats.