Children with autism spectrum disorders (ASD) experience high rates of anxiety, 
sensory processing problems, and gastrointestinal (GI) problems; however, the 
associations among these symptoms in children with ASD have not been previously 
examined. The current study examined bivariate and multivariate relations among 
anxiety, sensory over-responsivity, and chronic GI problems in a sample of 2,973 
children with ASD enrolled in the Autism Treatment Network (ages 2-17 years, 
81.6 % male). Twenty-four percent of the sample experienced at least one type of 
chronic GI problem (constipation, abdominal pain, bloating, diarrhea, and/or 
nausea lasting three or more months). Children with each type of GI problem had 
significantly higher rates of both anxiety and sensory over-responsivity. 
Sensory over-responsivity and anxiety were highly associated, and each provided 
unique contributions to the prediction of chronic GI problems in logistic 
regression analyses. The results indicate that anxiety, sensory 
over-responsivity and GI problems are possibly interrelated phenomenon for 
children with ASD, and may have common underlying mechanisms.