GI Problems and Autism: No Link Found
Overall No Link Between Autism and Gastrointestinal Disorders, New Study Shows
July 27, 2009 -- For years, a suspected link between gastrointestinal problems and autism has been debated, with medical reports describing GI symptoms in up to 84% of children with the developmental disorder.
The debated link has limited epidemiologic evidence but popular widespread acceptance, leading to the practice of placing some children with autism on restrictive diets.
Now, a new study from Mayo Clinic in Rochester, Minn., has found no apparent overall link between GI disorders and autism, although the researcher did find some individual GI problems are more common in children with autism.
''Nobody has done a population-based study to see if there is a difference in incidence of GI symptoms [in children with and without autism]," says Samar H. Ibrahim, MCChB, a pediatric fellow in gastroenterology and an instructor of pediatrics at the Mayo Clinic.
So Ibrahim and her colleagues did so.
GI Disorders &amp; Autism Link Study: Details
She compared 121 children with the disorder to a control group of 242 age-matched children without a diagnosis of autism, following them for a median (half longer, half less) of about 18 years. The children were all residents of Olmstead County, Minn.
Autism is typically seen in the first three years of a child's life, marked by difficulty in social interaction and communication, late talking, and restrictive or ritualistic behaviors.
"We compared the incidence of GI disorders in patients vs. controls," Ibrahim tells WebMD. She looked for specific GI diagnoses made before age 21, grouping them into five categories:
- Abdominal bloating, discomfort, or irritability
- Gastroesophageal reflux (acid reflux) or vomiting
- Feeding issues or food selectivity
"We did find that the overall incidence of GI symptoms was not different between the two groups," she says. But she did find that two specific problems -- constipation and feeding issues -- were more common in the children with autism.
Twice the proportion of children with autism had constipation than did the control group -- 33.9% vs. 17.6%. Although 24.5% of children with autism had feeding issues or food selectivity issues -- such as a feeding problem, lactose intolerance, loss of weight, or loss of appetite -- just 16.1% of the children without autism did.
In the study, the researchers found few children with autism with specific GI disease diagnoses, she says, although both groups had "nonspecific GI symptoms, such as complaints of abdominal pain. The frequency of GI symptoms among children with autism was about 77%, and 72% in those without it.
GI Disorders &amp; Autism Link: Interpretations
Explanations other than a GI disease probably explain the two GI symptoms found to be more common in the children with autism, Ibrahim tells WebMD.
Children with autism often show ritualistic tendencies and a need for routine, such as sameness in the diet. They may not drink enough water or take in enough fiber, practices that can lead to constipation and the feeding issues, she says.