Many individuals presenting with abdominal symptoms believe they are allergic or intolerant to various foods. This study assessed whether self-reported allergy is linked to a subsequent functional or organic diagnosis. 1000 new patients (42% male), attending a gastroenterology clinic completed a brief questionnaire immediately prior to being seen. The questionnaire asked about atopy, any believed drug allergies, and details of suspected food allergies and foodstuffs thought to worsen symptoms for which the patient was attending. Final diagnosis was made by case-note perusal. 28 asymptomatic patients seeking colon cancer screening advice were excluded. Of the remaining 972 patients, the final diagnosis was organic in 505 (52%), and functional in 467 (48%). Overall, 19% reported drug allergies (mainly antibiotics), 14% reported food allergies and 30% identified foods that worsened their symptoms. Foodstuffs to which patients perceived allergy /intolerance varied widely but dairy, wheat, fatty foods were the most common. Patients subsequently diagnosed with a functional disorder were more likely than those with organic disease to report drug allergies, food allergies or intolerances (table 1).

None of the 5 newly-diagnosed coeliac patients had recognised dietary gluten/wheat causing their symptoms. All 6 patients who were convinced they had coeliac disease had normal duodenal biopsies. Patients claiming drug or food allergies or worsening of symptoms with various foods are more likely to have a functional than an organic illness.