IL13 and irritable bowel syndrome: Interestingly, in one study, biopsy-secreted IL-13 was decreased as compared to controls in PI-IBS patients, who had a history of acute gastroenteritis with diarrhea and/or vomiting, (43), although in contrasting results, stimulated lymphocytes from IBS patients secreted more IL-13 as compared to controls, leading the authors to conclude that exposure to bacterial products led to a shift from a Th1 to a Th2 type of cytokine production (44).