Background: Attempts to diagnose and subtype irritable bowel syndrome (IBS) by symptom-based criteria have limitations, as these are developed in the West and might not be applicable in other populations.
Objectives: This study aimed to compare different criteria for diagnosing and subtyping of IBS in India.
Method: Manning's and the Rome I, II, and III criteria as well as the Asian criteria were applied to 1,618 patients (from 17 centers in India) with chronic lower gastrointestinal (GI) symptoms with no alarm features and negative investigations.
Results: Of 1,618 patients (aged 37.5 [SD 12.6] years; 71.2% male), 1,476 (91.2%), 1,098 (67.9%), 649 (40.1%), 849 (52.5%), and 1,206 (74.5%) fulfilled Manning's, Rome I, II, and III, and the Asian criteria, respectively. The most common reason for not fulfilling the criteria was absence of the following symptoms: "more frequent stools with onset of pain," "loose stool with onset of pain," "relief of pain with passage of stool," "other abdominal discomfort/bloating," and, in a minority, not meeting the duration criterion of 3 months/12 weeks. By stool frequency, constipation-predominant IBS (<3 stools/week) was diagnosed in 319 (19.7%), diarrhea-predominant IBS (>3 stools/day) in 43 (2.7%), and unclassified in 1,256 (77.6%). By Bristol stool form, constipation, diarrhea, and unclassified were diagnosed in 655 (40.5%), 709 (43.8%), and 254 (15.7%) patients, respectively. By their own perception, 462 (28.6%), 541 (33.4%), and 452 (27.9%) patients reported constipation-predominant, diarrhea-predominant, and alternating types, respectively.
Conclusion: By Manning's and the Asian criteria, a diagnosis of IBS was made frequently among Indian patients with chronic functional lower GI symptoms with no alarm features; the Rome II criteria gave the lowest yield. By the stool frequency criteria, a majority of patients had unclassified pattern, unlike by the stool form and patients' perception of their symptoms.