Satoyoshi syndrome is a rare postnatal disorder with muscle spasms, alopecia, and diarrhea of unknown etiology. Nutritional deficiency seems to influence lifespan. We present a patient with this syndrome having a unique "mesh-like" mucosal change radiographically and white granules endoscopically in the gastrointestinal tract. A common antibody against brain, stomach, and duodenal tissue, according to Western blot analysis, was detected in the sera of two patients with this syndrome. These findings suggest that Satoyoshi syndrome is a systemic autoimmune disease involving the nervous, endocrine, and gastrointestinal systems.