en Pediatric Pediatric Original Research Original Research <p dir="ltr" style="text-align: justify"><strong>Background: </strong>Functional gastrointestinal disorders (FGIDs) entail several distinct conditions that collectively account for a sizeable proportion of patients complaining of abdominal pain. Physicians&rsquo; awareness is fundamental to avoid unnecessary evaluations and to alleviate stress-related problems. This study aimed to assess the relative frequencies of FGIDs and related categories in a selected Iranian population.&nbsp;&nbsp;</p> <p dir="ltr" style="text-align: justify"><strong>Methods</strong>: We conducted this cross-sectional study in a gastroenterology clinic of a tertiary care pediatric hospital in Iran. Children and adolescents between the age of 4 and 18 years referred to the clinic from October 2011 to February 2013 were enrolled if they were diagnosed with FGID according to the Rome III criteria. A structured questionnaire was used to collect data on demographic characteristics, pain location, duration and frequency, associated symptoms, and pertinent family history. We used descriptive analyses to show mean (&plusmn;SD) and relative frequencies of categories of FGIDs.</p> <p dir="ltr" style="text-align: justify"><strong>Results</strong>: We diagnosed 183 (114 female) with FGIDs out of 1307 children and adolescents who were visited in the clinic. There was history of psychiatric disorders in 42 (22.9%) participants, and migraine headaches and gastrointestinal disorders were at least in one of the parents in 21 (11.5%) and 64 (34.9%) participants, respectively. We defined 84 (46%) patients under Irritable Bowel Syndrome (IBS) category, 38 (21%) under Abdominal Migraine, 26 (14%) under Functional Abdominal Pain, 21 (11%) under Functional Dyspepsia, and 7 (4%) under Functional Abdominal Pain Syndrome. Seven children (4%) had no defining feature for FGID categories and therefore labeled as unclassified.&nbsp;</p> <p dir="ltr" style="text-align: justify"><strong>Conclusion</strong>: FGID was a prevalent diagnosis among children and adolescents with abdominal pain. IBS was the largest category. Only a minority were unclassifiable under the Rome III criteria, indicating improved differentiation characteristics of Rome III criteria compared to the Rome II version.&nbsp;</p> Abdominal pain, Functional gastrointestinal disorders (FGIDs), Rome criteria, Children, Iran. 695 701 http://mjiri.iums.ac.ir/browse.php?a_code=A-10-1-907&slc_lang=en&sid=1 Elham Talachian talachian.e@iums.ac.ir 200319475328460020598 200319475328460020598 No Pediatric Gastroenterology division Ali-Asghar Children’s Hospital, Iran University of Medical Sciences, Tehran, Iran. Ali Bidari bidari.a@iums.ac.ir 200319475328460020599 200319475328460020599 Yes Emergency Department Hazrat-e-RasoulAkram Hospital, Iran University of Medical Sciences, Tehran, Iran. Hamed Zahmatkesh h.zahmatkesh67@yahoo.com 200319475328460020600 200319475328460020600 No