BackgroundUlcerative Colitis (UC) is a chronic disease characterized by inflammation of colonic mucosa. Environmental factors such as dietary patterns may increase symptoms in UC patients.AimTo validate and implement a questionnaire to identify foods that exacerbates symptoms in UC patients.MethodsA prospective cohort study was conducted to validate and to assess the relationship of food and symptoms in Mexican UC patients.ResultsThe IVC obtained was 0.56 in the questionnaire and kappa = 0.03 in foods from animal origin, 0.5 cereals and tubers, 0.2 legumes, 0.4 vegetables and fruits, 0.4 fats and 0.3 in others. The evaluation was carried out in UC patients (n = 233), 65% active and 35% in UC remission, the current age was 45 (SD; 15) years in active UC and 40 (SD; 15) years in UC remission. Three food groups were made based on the frequency of symptoms: Group A; symptoms more often, especially the active vs remission (P <0.05); Group B caused more symptoms in remission UC vs active UC (P = 0.07) and Group C caused more symptoms in the active UC (P = 0.05).ConclusionFoods with higher frequency of symptoms in patients with UC were: beans, whole milk, plum, lima beans and spicy sauce.