Eosinophil activation protein on GI-MAP refers to EDN/EPX, a protein associated with activated eosinophils. Eosinophils are immune cells. A stool protein measurement is different from counting eosinophils in blood or examining them in a tissue biopsy.
On this page
What the names mean
EDN stands for eosinophil-derived neurotoxin; eosinophil protein X is another name used in this context. Abbreviations can overlap across medical literature, so check the full assay name. The GI-MAP entry is a protein marker, not a parasite DNA target or a direct count of immune cells. [1]
Why researchers measure fecal EDN
Studies have examined associations between fecal EDN and eosinophil activity in intestinal tissue. For example, research in people with IBS compared stool findings with biopsy-related measurements. Such associations do not make this marker specific to one disease or establish why it is high in an individual. [2]
What a high result cannot diagnose
It cannot identify a specific food allergy, prove that a parasite is present or diagnose eosinophilic esophagitis (EoE). EoE assessment uses symptoms and esophageal biopsy findings, with evaluation of other causes; a stool protein is not a substitute. [3]
A normal EDN/EPX value likewise does not exclude every allergic or eosinophilic disorder. The result cannot locate the source of symptoms throughout the digestive tract or prescribe an elimination diet.
How it differs from calprotectin
Calprotectin reflects a different inflammatory-cell context and has different clinical uses. Neither marker should be treated as a universal inflammation score or used to diagnose a disease without clinical assessment. Comparing their numbers directly is not meaningful when methods and units differ.
Common questions
Is high stool EDN the same as a high blood eosinophil count?
No. They measure different things in different specimens. One cannot be substituted for the other.
Can it identify which food to avoid?
No. A nonspecific stool protein measurement cannot identify an individual food trigger or establish an allergy.
Sources and review
Sources checked October 7, 2026. Manufacturer material describes the test; clinical guidance and research support the interpretation limits.
- Diagnostic Solutions Laboratory: GI-MAP interpretive guide (manufacturer specifications)
- Casado-Bedmar et al.: Fecal EDN and mucosal eosinophil activity in IBS, 2022
- American College of Gastroenterology: Updated EoE guideline, 2025
Medical review of this article is pending. For a correction or source question, contact GI MAP Test.