INTRODUCTION: A growing body of evidence has pointed out the effectiveness of a diet low in fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) in patients with irritable bowel syndrome. However, there are no local studies to estimate the effects of this strategy on the symptoms and the health-related quality of life in these patients in Colombia or Latin America. OBJECTIVE: To determine the effect of a diet low in FODMAP on the quality of life and the severity of symptoms in patients with irritable bowel syndrome in Colombia. MATERIALS AND METHODS: We collected clinical and demographic information of all patients at the time of inclusion. Immediately afterwards, a trained interviewer applied the IBS-QoL survey to estimate the quality of life of patients. Then, we evaluated the intensity of the symptoms using an analogue visual scale, before and after the diet low in FODMAP. RESULTS: We included 50 subjects in the final analysis. We observed an increase in all the IBS-QoL scales (average increase in overall summary: 14.7 points, 95% CI: 9.4 to 20.1; p<0.001) and a significant reduction in all symptoms (-19.8 mm; 95% CI: 23.4 mm 16.2 mm; p<0.001). Sex, age, body mass index, socioeconomic status and the health care provider were not associated with the improvement in the health-related quality of life. CONCLUSION: A low diet in FODMAP reduced symptoms and improved quality of life in Colombian patients with irritable bowel syndrome. Controlled studies taking into account other factors linked to the severity of irritable bowel syndrome are required.