Monday, 21 February 2011

Should I mention gastrointestinal symptoms in autism?

There have been plenty of discussions, debates and controversies in autism research down the years. One of the first ones that I remember from a few years back was the issue of whether or not the hormone secretin could be a potential "treatment" for autism. Those who were around at the time of the secretin story will remember the hype, where newspapers, TV programmes and a young internet was awash with stories about this compound. I even remember our own research team doing a little bit of blue-sky thinking about secretin (and gastrin and CCK) at the time.

I am not going into the details of whether secretin was "right" or "wrong". Sure, there were quite a few studies suggesting that there was no universal effect from secretin but again, as per my mantra, science is about probability not absolutes; and autism is an extremely varied condition.

In the same year, the now widely discussed Lancet case series paper describing a specific pattern of bowel symptoms co-morbid to various presentations of autism and related conditions was also published and later retracted by the Lancet. The suggestion that a specific pattern of gastrointestinal histopathology may be present hit the world with a bang.

Both these areas of work have been, and in some cases, continue to be a major source of debate both within the autism community and also in the wider population. I am not getting into the nitty-gritty of such debates - there are plenty of other places on the Web to do that. What I would like to discuss further is the commonality between these two areas of research: the potential role of gastrointestinal symptoms / conditions being associated with some cases of autism.

A recent review article written by Chen and colleagues has been published reviewing the evidence for abnormal gastrointestinal histopathology in children with autism spectrum conditions down the years. Their conclusions after weighing up all the available evidence so far were: (a) GI findings in children with autism are inconsistent - aside from the finding of intestinal lymphonodular hyperplasia (LNH), (b) the present evidence does not support or refute a link between GI findings and autism, (c) the significance of LNH in this group is unknown.

Now, I am no Gastroenterologist - I can point to my gut (which seems to be growing as my years progress) but that is about the sum total of my expertise in this area so I can't claim to be an authority on the subject. What I can however offer is an opinion which is this: if the evidence is inconsistent and the significance of any gastrointestinal findings are not known, is it perhaps time to undertake a few more definitive studies to help try and answer these questions?

Some would say 'no' the book is closed - such invasive studies should not be done, the limited research money should be spent on other areas. Others might say we can still learn more about any connection between bowel symptoms (functional and histopathological) and autism, even if only for a proportion of people on the spectrum and perhaps just as important look at the various treatment measures to help alleviate any suffering as a result of any bowel problems irrespective of any autism connection (see here and my previous posts mentioning coeliac disease and autism).

In recent years it has become almost a dirty word to discuss the gut in relation to autism in some quarters. The title of this post is 'should I mention gastrointestinal symptoms in autism'. The question remains: should I?