Background Irritable bowel syndrome (IBS) is a functional disorder that leads to abdominal pain; its diagnosis is based on Rome IV criteria (recurrent abdominal pain at least 1 day per week in the last 3 months with more than two of the following: related to defecation, associated with a change in stool frequency and/or with a change in stool appearance). Objective To characterize an outpatient population diagnosed with IBS in Colombia during 2017–2018. Methods A cross-sectional study based on a review of clinical records of patients with a primary diagnosis of IBS. A representative sample of 380 individuals was recruited from a population of 38,182 people with a new diagnosis of IBS from a drug-claim database. Sociodemographic, clinical (symptoms, type of IBS, alarm features, etc.), treatment (pharmacological or not), and follow-up variables (for those with additional medical care at 3–12 months) were analyzed. The diagnosis and treatment used in the consultation were compared with clinical guidelines. Results Most of the 380 patients were women ( n  = 238; 62.6%), and the mean age was 40.1 ± 15.0 years. None of the physicians recorded the Rome IV criteria in the medical records. Unclassified IBS was the most prevalent subtype ( n  = 311; 81.8%), and the main symptom was abdominal pain ( n  = 327; 86.1%). Only 73 patients (19.2%) had follow-up data. The most frequently used drugs were aluminum hydroxide ( n  = 203; 53.4%) and hyoscine N -butyl bromide ( n  = 200; 52.6%). Regarding drugs included in the clinical practice guidelines, 19 people received loperamide (5.0%), 3 received trimebutine (0.8%), and 1 received sertraline (0.3%). Conclusions The patients were diagnosed without clearly established criteria, and they were treated symptomatically with little follow-up.