RÉSUMÉ
BACKGROUND: PI-IBS prevalence is around 10.1%-14.5% ≥ 12 months after infectious gastroenteritis in North America, Europe and Asia. However, there are no studies from Latin America. Two previous studies in Mexico suggest a low incidence of 5%. AIMS: to determine the prevalence of PI-IBS in patients attended in a tertiary-care center, as well as IBS subtypes, severity, other digestive symptoms and red flags vs nPI-IBS. METHODS: seventy IBS patients screened for immunological research completed the Rome III, Spiller's for PI-IBS and IBS-SSS questionnaires. PI-IBS prevalence was determined according to three criteria sets. C1: ≥ 2 episodes of sudden onset, onset while traveling, initial illness with any of the following symptoms, fever, vomiting, bloody diarrhea and a positive stool culture. C2: sudden onset and > 2 episodes of fever, diarrhea, vomiting and bloody diarrhea. C3: sudden onset after an infectious episode such as a positive culture or onset with ≥ 2 episodes of fever, vomiting, diarrhea, rectal bleeding and foreign travel. Items were dichotomized as present or absent and compared using the Fisher's exact and Mann-Whitney U tests. RESULTS: PI-IBS prevalence was as follows. C1: 5.7%, C2: 0 and C3: 1.4%. There were no IBS-C or IBS-M cases. In the C1 group, one case was mild and three were moderate IBS, which was similar to the non PI-IBS group. One case in the C3 group had mild IBS. There were no differences in the frequency of esophageal, gastroduodenal, anorectal, bloating/distension and red flags between PI-IBS and non PI-IBS groups (analyzed only for C3). CONCLUSIONS: in Mexico, there is a very low prevalence of PI-IBS in patients from a tertiary-referral center. However, it varies according to the surrogate-criteria used. The later needs to be taken into account when performing PI-IBS studies.