Irritable bowel syndrome (IBS), sometimes referred to a ‘functional bowl disorder’ (FBD) is characterised by symptoms such as abdominal bloating and discomfort, and constipation and/or diarrhoea. Its cause is often said to be unknown. However, in practice I find two approaches to be generally effective in combating the symptoms of IBS. These are:
1. Identification and elimination of food triggers.
2. Correction of any underling imbalance there may be in the ‘ecosystem’ within the gut.
It is possible that any food can trigger IBS symptoms, but my experience in practice is that wheat is the number 1 offender. Now, sometimes wheat sensitivity is caused by a sensitivity to a protein found in wheat (as well as oats, rye and barley) known as gluten. In conventional medicine, gluten sensitivity is a recognised conditions that goes by the name of coeliac disease. This can be tested for using blood tests and biopsy of the lining of the small bowel.
If the tests come back as positive coeliac disease is diagnosed. If they come back as negative it is often assumed that not only is their no coeliac disease, but there’s no sensitivity to wheat/gluten either. But is this really so?
I have seen over the years many patients who have turned up negative test results for coeliac, who nonetheless have IBS symptoms that seem to have a very clear relationship with wheat consumption. Last year, for instance, I wrote about a four-year-old girl whose parents told me she got diarrhoea when she ate wheat, but had no diarrhoea if she didn’t. The test of coeliac disease was negative, and her dietician (with the support of her gastroenterologist) enthusiastically advocated a diet for this child that was full of grain-based foods including wheat.
So, what are we to make of individuals who don’t appear to have coeliac disease but nonetheless appear to react adversely to wheat? Well, it’s possible that individuals may react to wheat in a way or through mechanisms that are not necessarily related to full-blown coeliac disease. This concept was put forward recently in a paper which appeared in the American Journal of Gastroenterology . Doctors based at McMaster University in Hamilton, Canada and the Mayo Clinic, Minnesota, USA, put forward the idea that gluten can induce symptoms similar to FBD, even in the absence of fully developed celiac disease.
In short, just because someone doesn’t have coeliac disease, doesn’t mean their bowel symptoms are not due to gluten.
Some people are keen to be tested for food sensitivity, though my experience in practice is that no tests are foolproof. One reason for this is that the body can react to food through several mechanisms. Let’s imagine that someone has a food sensitivity as a result of an antibody reaction to that food. If the test being used specifically looks for this antibody then it’s got a fair chance of picking up the problem. However, if it’s testing for something else, then it’s unlikely to identify the problem.
One simple but often effective way of identifying food sensitivities is to eliminate foods to see if it helps. One problem here is that some individuals are sensitive to a range of foods, and if all of them are not removed, symptoms may persist even though problem foods have been eliminated. To be on the safe side, I tend to recommend that when they take out wheat, they take out other gluten-containing grains as well as dairy products.
In my experience, the overwhelming majority of IBS sufferers improve dramatically on this regime. Foods can be added back into the diet (about one every 2 days) to see which foods cause a return of the IBS symptoms.
Verdu EF, et al. Between Celiac Disease and Irritable Bowel Syndrome: The “No Man’s Land” of Gluten Sensitivity Am J Gastroenterol 19 May 2009 [epub ahead of print publication]