Histopathological alterations in post-infectious irritable bowel syndrome in Bangladeshi population

Irritable bowel syndrome (IBS) is the most common gastrointestinal disorder encountered in general practice. Although enormous progress in the pathogenesis of IBS has been made, it is still poorly understood. A significant proportion of patients with IBS, report onset of symptoms following an episode of acute gastroenteritis. Aim of the study was to determine whether post infective irritable bowel syndrome (PI-IBS) has histological or clinical features that are distinct from those of IBS patients with no history of preceding infection. A total of 50 consecutive IBS out patients and 10 healthy control subjects completed a questionnaire detailing symptoms, mode of onset, and previous psychiatry history. All underwent a full diagnostic workup including colonic biopsy and histopathology. Patients were divided according to onset of symptoms into post infectious IBS (PI-IBS, N=18) and non-post infectious IBS (non-PI-IBS, N=32) patients. Diarrhea predominantly occurred more frequently in PI- IBS (70%) than in non-PI-IBS (40%) patients (p<0.05). Histopathological examination of the biopsy specimen from the sigmoid colon of the observed individuals showed a significant increase in the number of chronic inflammatory cells in both groups of IBS patients comparing to the control group (p<0.001). Lymphoid follicles were increased in both groups of IBS patients in comparison to control group (p<0.05). Mast cells were increased in IBS patients comparing to the control group (p<0.05) and it was significantly increased in the PI-IBS patients than the non-PI-IBS patients (p<0.001). Individuals with PI-IBS are clinically distinct subgroup characterized by predominant diarrheal symptoms and increased mast cells compared to those with non PI-IBS.