Early studies suggest that there is a connection between gut problems and brain problems in people with autism.

Patients with autism may complain of pain, bloating, and/or diarrhea. These gut problems cannot be described simply as Crohn's disease. This case study describes two patients with autism and problems in the gut. Some people think that the gut problems are caused by an immune response to proteins in the diet. Autism patients and their families often report that special diets such as gluten-free and casein-free diets help with gut problems and symptoms of autism. The authors suggest that doctors refer patients with autism for a work-up and treatment of gut symptoms.