Exploring small intestinal bacterial overgrowth in functional upper gastrointestinal disorder: A comprehensive case-control study.

Background: Small intestinal bacterial overgrowth (SIBO) is suspected and excluded frequently in functional gastrointestinal (GI) disorders. Children presenting with various esophago-gastro-duodenal (upper GI) symptoms are rarely subjected to investigations for SIBO.

Aim: To estimate the frequency of SIBO in children having functional upper GI symptoms (as cases) and to compare the result of the SIBO status to that of the controls.

Methods: Children aged 6 to 18 who presented with upper GI symptoms were selected for the study. All children were subjected to upper GI endoscopy before being advised of any proton pump inhibitors (PPIs). Children with normal endoscopy were assigned as cases, and children having any endoscopic lesion were designated as controls. Both groups were subjected to a glucose-hydrogen breath test by Bedfont Gastrolyser.

Results: A total of 129 consecutive children who were naive to PPIs and had normal baseline investigations were included in the study. Among them, 67 patients had endoscopic lesions and served as the control group, with six cases being excluded due to the presence of Helicobacter pylori in gastric biopsies. Sixty-two children with normal endoscopy results formed the case group. In the case group, 35 children (59%) tested positive for hydrogen breath tests, compared to 13 children (21%) in the control group. The calculated odds ratio was 5.38 (95% confidence interval: 2.41-12.0), which was statistically significant. Further analysis of symptoms revealed that nausea, halitosis, foul-smelling eructation, and epigastric fullness were positive predictors of SIBO.

Conclusion: It is worthwhile to investigate and treat SIBO in all children presenting with upper GI symptoms that are not explained by endoscopy findings.