Autism Associates of New York

Pediatrics. Vol 125, No. 2. Feb 2010
The authors from the  Psychosocial Department and Department of Gastroenterology,University of Amsterdam, Netherlands
concluded that behavior problems are common in children who have constipation and are referred to gastrointestinal outpatient clinics, suggesting that a behavioral screening should be incorporated into the diagnostic workup of children with constipationl.

And "they" say that abnormal gastrointestinal function has nothing to do with autism!