Irritable bowel syndrome: in search of an etiology: role of Blastocystis hominis

Javed Yakoob, Aga Khan University
Wasim Jafri, Aga Khan University
Nadim Jafr, Aga Khan University
Rustam Khan, Aga Khan University
Muhammad Islam, Aga Khan University
Mohammad Asim Beg, Aga Khan University
Viqar Zaman, Aga Khan University

Abstract

This study was designed to examine stool specimens of irritable bowel syndrome (IBS) patients for Blastocystis hominis, a common intestinal parasite. One hundred fifty patients were enrolled, 95 IBS cases and 55 controls. These patients provided a medical history, and underwent physical and laboratory evaluations that included stool microscopy and culture for B. hominis and colonoscopy. The 95 cases (51 males and 44 females) had a mean ± SD age of 37.8 ± 13.2 years. Stool microscopy was positive for B. hominis in 32% (30 of 95) of the cases and 7% (4 of 55) of the controls (P = 0.001). Stool culture was positive in 46% (44 of 95) of the cases and 7% (4 of 55) of the controls (P < 0.001). Stool culture for B. hominis in IBS was more sensitive than microscopy (P < 0.001). Blastocystis hominis was frequently demonstrated in the stool samples of IBS patients; however, its significance in IBS still needs to be investigated. Stool culture has a higher positive yield for B. hominis than stool microscopy.