Gastrointestinal symptoms

What is the link between gastrointestinal symptoms and autism?

Autistic people have more digestive problems than those without.

What are gastrointestinal symptoms?

Gastrointestinal symptoms include all the unpleasant sensations and difficulties associated with digestion. To digest, the human body collaborates with dozens of species of bacteria present in the body. These bacteria are our friends. Autistic people often have fewer species of bacteria in their bellies, which can cause problems at certain stages of digestion. Also, people who are very selective in their food and eat little variety have fewer species of bacteria in their bellies. Having the help of a nutritionist to vary your food routine can help.


Link to autism

46% of autistic people have gastrointestinal symptoms
22% of autistic people suffer from constipation.
13% of autistic people have diarrhea.

(Holingue et al., 2018)

Diets and autism

Some people claim to cure autism with diets. This is totally false, and not only can it generate new health problems, but some families have gone into debt by giving credence to the claims of charlatans.

The nuance of diet and autism

As many autistic people have gastrointestinal problems and sometimes severe intolerances to certain foods, this inevitably causes them health problems. Very often, it also causes discomfort and even pain that is very difficult to bear. Add to this the fact that many are hypersensitive, and others can’t explain their discomfort or pain, and there’s a good chance that these peculiarities have a direct impact on the way autistic people function.

Pain or illness as an obstacle to development

Someone who is uncomfortable or in pain won’t be able to learn. That’s why certain diets can help some autistic people. Diet as such has nothing to do with autism; it will never cure it. But if the autistic person is intolerant to a food, for example, and the pain is taken away through dietary modifications, it’s quite possible that they will be better able to progress because that’s what they would have been able to do were it not for the disruptive element of gastrointestinal pain.


It's vital to talk to specialists when considering a diet. Autistic people often have dietary deficiencies due to their particularities, and certain approaches can worsen existing health problems or cause new ones.

Catherine Bouchard-Tremblay

Science popularizer