Background and Objectives: Chronic abdominal pain (CAP) in children may be a precursor to irritable bowel syndrome (IBS) in adults. The prevalence of abnormal lactulose breath tests (LBT) suggesting small intestinal bacterial overgrowth (SIBO) has been reported as 91% in children with CAP and 35% in healthy controls. In addition, patients with IBS with SIBO who responded to nonabsorbable antibiotic treatment with normalization of LBT reported 75% global improvement in symptoms. The aim of the study was to test whether treatment with a nonabsorbable antibiotic may reduce symptoms in children with CAP.
Methods: Seventy-five children ages 8 to 18 years with CAP based on Rome II criteria were enrolled. Subjects underwent baseline LBT and completed symptom-based questionnaires. They were then randomized in a 2:1, double-blind fashion to receive a 10-day course of 550 mg of rifaximin or placebo 3 times per day (t.i.d.). LBT and questionnaires were repeated 2 weeks after treatment.
Results: Forty-nine children received rifaximin and 26 received placebo. There were no differences in demographics between groups. Ninety-four percent who received rifaximin and 92% who received placebo had abnormal baseline LBT, suggesting SIBO (not significant [NS]). There was no significant difference in symptom improvement between groups; however, only 20% of children treated with rifaximin achieved a normalized repeat LBT, demonstrating successful treatment of SIBO.
Conclusions: Similar to adults with IBS, the prevalence of abnormal LBT suggesting SIBO in children with CAP is high; however, treatment with 10 days of rifaximin has low efficacy in normalizing LBT in this group. Additional studies are needed to determine whether a treatment approach with higher efficacy would lead to improvement in children with CAP.
*Division of Gastroenterology and Nutrition, Children's Hospital Los Angeles and Keck School of Medicine, University of Southern California, Los Angeles, USA
†Gastroenterology Section, New Mexico VA Health Care System and the University of New Mexico, Albuquerque.
Received 23 April, 2010
Accepted 1 July, 2010
Address correspondence and reprint requests to Brynie Slome Collins, MD, Division of Gastroenterology and Nutrition, Children's Hospital Los Angeles, MS #78, 4650 Sunset Blvd, Los Angeles, CA 90027 (e-mail: firstname.lastname@example.org).
The present study was supported by the Saban Research Institute Research Career Development Fellowship Award, Clinical Research Academic Career Development Award, and the CHLA General Clinical Research Center (GCRC) through NIH NCRR GCRC Grant MO1 RR-46. It was also supported, in part, by an unrestricted grant from Salix Pharmaceuticals. Salix played no role in the conception of the hypothesis, experimental design, conduct of the study, data analysis, or preparation of the manuscript.
Dr Lin has IP rights in a related area. Dr Lin is supported by the NIH, the VA, and the Department of Defense.
ClinicalTrials.gov Identifier: NCT00619970.
The authors report no conflicts of interest.