Fructose malabsorption is not uncommon among patients with irritable bowel syndrome in India: a case-control study

Fructose malabsorption (FM) is reported in 38 % to 75 % patients with irritable bowel syndrome (IBS). Most of these studies, however, had limitations due to use of variable dose of fructose, small sample size, and lack of control population. Moreover, there is no study on this issue from India. Hence, in this prospective study, we evaluated the frequency of FM on an adequately powered sample of patients with IBS and healthy controls (HC) from India.

Ninety-seven patients with IBS (diagnosed using Rome III criteria) and 41 healthy controls were evaluated for FM by fructose hydrogen breath test (FHBT) using 25 g fructose. Persistent rise (at least two readings) in breath hydrogen 20 parts per million (PPM) above basal was considered diagnostic of FM.

Patients and controls were comparable in age (37 years [21-66] vs. 33 years [15-56]; p = 0.1) and gender (76/97 [78.4 %] vs. 29/41 [70.7 %] male; p = 0.3). Of 70 patients reporting data on Bristol's stool forms, 10 (14 %), 43 (61 %), and 17 (25 %) had constipation, diarrhea predominant and unclassified IBS (Asian classification), respectively. Patients with IBS more often had FM than controls on FHBT (14/97 [14.4 %] vs. 1/41 [2.4 %]; p = 0.04). Patients with FM more often had diarrhea-predominant IBS than those without FM (10/11 [91 %] vs. 33/59 [56 %]; p = 0.02).

Though FM was not very common among Indian patients with IBS, it was higher among them than controls. Patients with FM more often had diarrhea-predominant IBS.