The relationship between the irritable bowel syndrome (IBS) and food intolerance is not clear. We studied the cutaneous response to food antigens in 43 volunteers who were students and employees of the Faculty of Medicine of Universidade Federal Fluminense. Subjects were divided into 3 groups after evaluation for Roma II criteria for functional disease of the gastrointestinal tract: group I, 14 volunteers with IBS; group II, 15 volunteers with functional dyspepsia; group III, 14 volunteers without habitual gastrointestinal symptoms. The subjects were submitted to the skin prick test with 9 food antigen extracts, for a total of 387 skin tests (9 per volunteer). Of the 126 tests applied to group I, 24 (19.4%) were positive (a 3-mm wider papule than the negative control) and of the 135 tests applied to group II, 3 (2.3%) were positive. Of the 126 tests applied to group III, 6 (4%) were positive. The number of positive responses obtained in group I (IBS) differed significantly from the other 2 groups (P < 0.01). None of the volunteers with IBS reported intolerance to any isolated food. The higher reactivity to food antigens in group I compared to groups II and III suggests that intestinal permeability may be increased in patients with IBS.

-Context -The irritable bowel syndrome and primary headache are two chronic diseases characterized by symptoms of recurring pain and affect approximately 10%-20% of the general population. Objectives -To study the prevalence of primary headache in volunteers with irritable bowel syndrome in a Brazilian urban community. Methods -It was evaluated the prevalence of primary headache associated with irritable bowel syndrome in adult volunteers 330 no patients.The protocol included the Rome III criteria, international classification of Headaches, later divided into four groups: I-Irritable bowel syndrome (n = 52), II-Primary headache (n = 45), III-Irritable bowel syndrome (n = 26) and headache, and IV-Controls (207). Results -We not found significant difference in the average age of the four groups and the diagnosis of irritable bowel syndrome, primary headache and their association was more frequent in females. The frequent use of analgesics was greater in groups II and III. Conclusion -Our results suggest that irritable bowel syndrome and primary headache are also common in third world countries. The frequency in use of analgesics in association between the two entities was relevant. The identification of irritable bowel syndrome patients with different clinical sub-types could improve the therapeutics options and the prevention strategies. HEADINGS -Irritable bowel syndrome. Headache. Comorbidities.