Gastrointestinal disorders and autism

by Benison O'Reilly on Wednesday, February 3rd, 2010

Parental anecdotes suggest that gastrointestinal disorders such as abdominal pain, constipation and chronic diarrhoea are more common amongst children with ASDs than in their typical peers. But are they really more common, or do parents of children with autism just look more strenuously for physical complaints that might explain their child’s odd and unsettling behaviours? Or maybe GI problems are more common in a subset of individuals with an ASD and the majority of kids on the spectrum remain unaffected?

The jury is still out. The reported prevalence of gastrointestinal symptoms in children with ASDs has ranged from 9% to 70% depending on the type of study used to assess this.(1) As it seems with most health issues associated with autism, the research surrounding this topic is patchy and often of fairly low quality, leaving lots of questions unanswered.

At last the mainstream medical community has tackled this evidence gap and produced a report with the ponderous title: Evaluation, Diagnosis, and Treatment of Gastrointestinal Disorders in Individuals with ASDs: A Consensus Report. Consensus reports are just that: a group of experts get together and reach a consensus, based on their own clinical experience and the existing evidence. In this particular case the experts came from a wide variety of disciplines: child psychiatry, developmental paediatrics, epidemiology, medical genetics, immunology, nursing, paediatric allergy, paediatric gastroenterology, paediatric pain, paediatric neurology, paediatric nutrition, and psychology.

The report is not without controversy, as it questions some accepted beliefs, or rather beliefs accepted by many parents and ‘biomedical’ practitioners working outside the mainstream. For example

• The existence of a gastrointestinal disturbance specific to persons with ASDs (eg, “autistic enterocolitis”) has not been established.

• The evidence for abnormal gastrointestinal permeability [in other words ‘leaky gut’] in individuals with ASDs is limited. Prospective studies should be performed to determine the role of abnormal permeability in neuropsychiatric manifestations of ASD

• Available research data do not support the use of a casein-free diet, a gluten-free diet, or combined gluten-free, casein-free (GFCF) diet as a primary treatment for individuals with ASDs.(1 )

Science-speak, sorry. Scientific writing is almost always like that; everything is qualified. It’s the nature of science—nothing is considered ‘proven’ until there is an overwhelming body of good quality evidence to support it—but unfortunately this sort of language sounds wishy-washy to parents desperately seeking answers.

Anyway, there are some significant breakthroughs contained in this report; in particular  it recognises that in individuals with an ASD and limited communication skills, gastrointestinal complaints (e.g. abdominal pain) may manifest themselves as problem behaviours like sleep disturbance, aggression and self-injury, and that physical causes for problem behaviours should be considered if a child with autism starts to act up unexpectedly. When it comes to investigating GI complaints we need to be particular vigilant with individuals who lack the ability to communicate their distress.

The report also calls for lots more research and recommends that all clinical studies include a genetic testing component, in the hope of identifying particular genotypes of children with ASD who are more prone to GI complaints.

For those who are interested, the report was published in the January issue of the medical journal Pediatrics and is free to download at: http://pediatrics.aappublications.org/cgi/content/full/125/Supplement_1/S1

1. Buie T, Campbell DB, Fuchs GJ, et al. Evaluation, Diagnosis, and Treatment of Gastrointestinal Disorders in Individuals with ASDs: A Consensus Report. Pediatrics 2010;125:S1–S18

Tags: autism, diet, gastrointestinal, treatments