Pathogenesis of allergic gastroenteropathy involves various antigen-mediated allergic reactions through a defensive mechanism of the digestive tract. The conventional method of the diagnosis generally involves the exclusion-provocation test of causative food and the judgement based on only subjective symptoms. A diagnostic method based on objective parameters has not been established yet. To establish an objective diagnostic method, ultrasonography was applied to 3 patients in whom chicken eggs and milk had been clinically diagnosed as the antigens during the oral loading test of appropriate antigen extract. After oral loading of the causative antigen extract, the gastric movements were observed by ultrasonography from 30 minutes before loading until 120 minutes after loading. The total number of peristaltic movements were then measured during every 30 minuites as an indicator of acceleration of gastric peristalic movenents. All 3 cases showed a marked acceleration of gastric peristaltic movements as well as several abdominal symptoms such as abdominal pain and diarrhea at 30 to 60 minuites after loading the antigen. These findings indicate that this method may be useful in the diagnosis of allergic gastroenteropathy.