The child with autism: GI findings and diet guidelines

In 2000, I presented* my research on 22 children with autism who had diarrhea. (I also took care of others with normal bowel movements or constipation, but for this particular review, I studied those who had diarrhea.) 

It was an interesting group. They varied widely in age: 28 months to 22 years, and 16 (73%) were males. They averaged 2.3 foul, unformed bowel movements (stools) daily, again with a wide range: 1 every other day to 5 per day.

Half (11) were on a gluten-free, casein-free diet when they came to me, but according to their parents, only four of those had better behaviors or fewer, thicker bowel movements on the restricted diet. Most of the children were on various vitamins, minerals or supplements (some were taking more than 10 supplements). 

Their physical examinations were essentially normal except for their autistic activities, and most were severe. What stuck out is that despite their often limited or restricted diets, most had grown exceedingly well. In fact, the majority (14, or 64%) were actually above the 75% for height or weight when we would only expect a quarter (five or six) to be that big.

Most of their laboratory tests were normal too, including antibodies to a fraction of the gluten molecule. Of course, that could also have been because many were already gluten restricted. A number had low zinc (which is often because of diarrhea) and a quarter of those tested (four of 17) had increased fat in their bowel movement. 

As a result of these tests, seven of the children underwent upper endoscopy and pancreatic stimulation testing. Some of the parents hoped that secretin, the hormone we used to stimulate the pancreas, would help their children. This was based on an earlier report that secretin made some children better, though our patients weren't any different after the testing, and later studies from our center and Emory contradicted the earlier findings. 

The Findings

Our results were interesting. One child had a duodenal ulcer and five others had mild irritation of their stomach or duodenum, the first part of the small intestine (this is gastritis or duodenitis). And six of the seven children tested had abnormalities in the amount of pancreatic enzymes produced.

Even better, the one child with the ulcer improved on treatment and five of the six who were started on pancreatic enzymes had better bowel movements; three were able to be toilet trained; and all of these parents reported an improvement in behavior or communication over a 6-month period. 

What Do the Findings Mean?

A significant number of children with autism spectrum disorders have GI issues (and this has been born out in other studies). But because they can't communicate them, parents and doctors have to depend on subtle signs to recognize and detect them. And when the problems are corrected, these children often feel better, and as a result, their behaviors may improve.  

A gluten-free, casein-free diet does seem to help a small number of these children (perhaps 25% based on our findings). But if it doesn't help with a month or two, it may not be worth continuing. The same may be true of the supplements that many of these children are given.

Consultation with a pediatric gastroenterologist knowledgeable in this area, and stool testing may be helpful in pointing out children who might benefit from further evaluation or treatment. 

Other Thoughts

I am not sure why so many of those with autism grow so big. Maybe they do have more and better selective intestinal absorption of some nutrients. Research needs to move in that direction, since that may influence other factors in their chemistry. (But remember, this is just my opinion and speculation).

Knowledgeable pediatric dietitians can help guide parents, after reviewing the child's intake. It's safest to depend on ones who are referred to by your pediatric gastroenterologist, and to be wary of any that sell the vitamins or supplements they recommend.

We are still at the beginning of putting these diet and behavior pieces together, and we're still struggling but wanting to figure it out. We obviously know that they do fit. You may be able to understand some of what triggers your child's problems by keeping a symptom diary. We have one for you to use with all the instructions to help you try to pinpoint what may be causing particular behaviors.

• At the annual meeting of the North American Society for Gastroenterology, Hepatology and Nutrition (NASPGHAN)