The diagnosis of autoimmune enteritis is based on clinical features, pathologic features, antibody positivity, and treatment. 1. Clinical features: chronic diarrhea with a duration of more than 6 weeks, malnutrition, and ineffective gluten-free diet. 2. Pathological features: localized or widespread atrophy of small intestinal villi, deep cryptitis, increased crypt apoptotic vesicles, and decreased intraepithelial lymphocytes. Positive anti-intestinal epithelial cell antibodies or anti-cuprocyte antibodies. 3. Antibody positive: positive anti-intestinal epithelial cell antibody or anti-cupressor cell antibody. 4. Therapeutic aspects: immunosuppressive therapy is effective. At present, autoimmune enteropathy is rare and the mechanism is not yet clear, so if you suspect that you have autoimmune enteritis, it is recommended that you seek early medical attention and get a clear diagnosis with the help of your doctor.