Autoimmune enteropathy (AIE)

Autoimmune enteropathy is a rare condition affecting the small intestine, in which immune dysregulation is understood to drive an attack on the cells lining the gut, flattening the villi so the bowel cannot absorb nutrients normally. It is seen most often in infants, where it typically appears within the first six months of life as severe, treatment-resistant diarrhea, and it has also been documented in adults, where it can be harder to recognize because it overlaps with other digestive disorders such as celiac disease. In some children, the condition traces to a specific gene mutation that disrupts a regulatory immune cell responsible for keeping the immune system in check.

Because it is rare, research describes reliable prevalence figures as limited, and diagnosis relies on clinical evaluation, blood antibody testing, and biopsy findings.

Common signs

Severe, watery, hard-to-control diarrhea is the central feature, along with poor nutrient absorption, weight loss, and, in children, failure to grow as expected. Dehydration and nutrient and protein loss can follow, and some people have signs of immune involvement in other organs.

This is a plain-language summary for orientation, not a diagnosis. Mechanisms are described as current understanding, not settled fact. Work with your own clinician for your care.