Frequency of Food Hypersensitivity in Patients With Functional Gastrointestinal Disorders

Abstract

Introduction: Food hypersensitivity (FH), irritable bowel syndrome (IBS) and functional dyspepsia (FD) have many overlapping symptoms, including abdominal discomfort, bloating and altered bowel habits, making it challenging to distinguish between the disorders. However, symptoms of FH reduce on elimination diets and relapse on a subsequent food challenge, which does not happen in IBS/FD. Up to 25% of patients with IBS may have FH. However, mostly Caucasian populations have been studied, in which the type of food consumed, and the tendency to form antibodies against common foods may be completely different compared to the south Asian population. We aimed to determine the frequency of FH in patients with IBS and FD. Methods: Adult patients diagnosed with IBS and/or FD as per the Rome III criteria were recruited. Patients underwent serological testing against 6 main food allergens: beef, shrimp, egg white, milk, peanut, and soy-bean. Those testing positive were subjected to a food elimination diet for 4 weeks. Those showing improvement on an elimination diet were subjected to re-challenge. Changes in symptoms were documented at all stages by the well validated Global overall improvement scale (GOS) and Gastrointestinal symptom rating scale(GSRS), and a food diary was maintained.Figure: Flow of the study.Figure: Baseline GSRS and GOS scores of the cohort.Figure: Changes in GSRS and GOS in patients with food hypersensitivity after elimination diet and food re-challenge.Results: Two hundred patients with IBS/FD were screened. The average age of the patients was 38.6, and 55 % were male. Nineteen (38%) patients tested positive on serological testing, and were subjected to a food elimination diet. The most common food hypersensitivity was shrimp (17/89%), followed by 4 (21%) for egg-white, and 2 (10%) each for peanut and soya bean. Off these, 8 showed improvement. They were re-challenged, and were evaluated 2 weeks later, when all suffered symptom relapse. These 8 (4%) patients were diagnosed with FH. There was a statistically significant difference in both GSRS (total and component) and GOS scores at baseline between patients testing (+) and (-) on food allergen testing, mainly for diarrhea (P=0.001), abdominal pain (P=0.001) and indigestion P= Conclusion: Standardized methods were used for the diagnosis of a FH in IBS-D and FD patients. FH was present in 4 % of patients' with IBS/FD. This is compatible with literature that reports a range from 1.7-5.3%, and lower in this particular cohort than previously reported. We conclude that exclusion of a FH may be helpful in a subset of IBS/FD patients with a compatible clinical history, and intractable symptoms.