The role of food hypersensitivity (or intolerance or delayed allergy) in the origin of IBS (irritable bowel syndrome) has been proven.

Italian version

In the July issue of the American Journal of Gastroenterology (Zar S, Benson MJ, Kumar D. Am J Gastroenterol. 2005 Jul;100(7):1550-7) British researchers have confirmed the role of food hypersensitivity (or intolerance or delayed allergy) in the origin of irritable bowel syndrome.

Since there are no existing conventional tests for this diagnosis, only non-conventional tests are accepted at present. One of these identifies the IgG4's in relation to certain antigens. The researchers compared the resulting data of the IgE evaluation by way of the RAST test as well as by way of the Prick Test (SPT) in relation to 16 common foods in Great Britain.

The subjects with IBS showed a marked increase in IgG4 intensity in relation to certain foods for which no IgE reaction was found. A direct IgE reaction was never present except in some isolated cases (1 positive reaction in 5 out of 56 patients) for the Skin Prick Test.

The higher or lower intensity of IgG4 was not correlated with the severity of the syndrome.

Therefore it's clear that the diagnosis of food intolerances CANNOT be accomplished by way of IgE dosage and that an IgG test can be useful.

As we've pointed out in other occasions, remember that the IgG4 dosage can be interpreted as a signal of intolerance, but also as a signal of recovery; During the recovery of immunological tolerance, the IgG4's progressively increase while tolerance is being regained.

So, when faced with a diagnosis of a food intolerance that has been performed with an IgG4 test, it's obvious that one must carefully consider the possibility of eliminating certain foods.

If one excludes foods from his diet, he might interfere with the body's effort to regain tolerance and this would be dangerously counterproductive.

A diet that encourages tolerance recovery and food reintroduction (based on the results of a DRIA test , for example) is a safe way to treat these patients.

Italian version