Do GI problems cause autism spectrum disorder (ASD)?

As of now, there is no scientific proof that GI problems directly cause ASD. It is possible that some people have genes that cause ASD and also cause GI problems. There is no evidence that children with ASD have abnormalities in their intestines, or overgrowth of yeast, or other organisms that make behaviors worse.

Should I be concerned if my child with ASD has GI problems?

A child with ASD who has GI problems should be examined just as any other child would be. Constipation and diarrhea may be caused by diet, so children who are picky eaters may be at higher risk depending on what they eat and drink. Children with ASD may not be able to tell people about GI pain and may therefore show it through other behaviors. For example, if they have stomach pain, they may act out as a way to let parents know because they cannot talk. Children who have trouble toilet training and those who don't get enough fiber may develop constipation.

How will my child's pediatrician know whether my child has GI problems?

A pediatrician will talk to you and do a physical examination. She will ask about diet history and weight gain. The doctor may request an evaluation by a pediatric gastroenterologist (a doctor with additional training in GI diseases) or nutritionist or request laboratory tests. As of now, children who do not have signs of GI problems should not have any special tests. The pediatrician might consider specialized evaluations if a child has signs of GI problems. For example, the doctor might use an x-ray to find out more about severe constipation. Some children do not digest milk well and benefit from trying a milk-free diet or enzyme replacement to help digest "milk sugar" (lactose). This is a common problem. Rarely, children will have an immune response to gluten (celiac disease) and need to avoid wheat and other grain products. There is a blood test your child's pediatrician can do to determine whether your child needs to see a specialist to evaluate for celiac disease. For ongoing GI problems, your child's doctor might refer your child to a gastroenterologist to get a more in-depth look at your child.

How will my child's pediatrician treat my child?

If medical testing shows that your child has a GI problem, a pediatrician will recommend treatment for that problem. Treatments may include extra fiber in the diet, stool lubrication or stool softener for constipation, more tests for gastroesophageal reflux, or medications.

Sometimes, families take out milk or wheat from their child's diet to test for relief of GI symptoms with the hope that other behaviors of ASD will improve. This gluten-free/casein-free dietary treatment is popular, but there are little scientific data supporting its general use. Some children might have symptoms of lactose intolerance (intolerance of milk sugar). Getting rid of milk will decrease chance of irritation and harden loose stools in affected children. Celiac disease (a reaction to gluten proteins in barley, rye, and wheat) is found in 1 in 100 people. Children with ASD, especially if they have a family history of celiac disease, should be screened if they have any stomach pain or problems with bowel movements, slow growth, or poor appetite.

With ongoing research, doctors will keep learning about GI treatment of children with ASD.