Double-blind, placebo-controlled antibiotic treatment study of small intestinal bacterial overgrowth in children with chronic abdominal pain.
OBJECTIVE
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, CA 90027, USA. bcollins@chla.usc.edu
Brynie Slome
BS
Collins
Henry C
HC
Lin
D015746:Abdominal Pain / Q000209:etiology / Q000517:prevention & control*; D000293:Adolescent; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000627:therapeutic use*; D001944:Breath Tests; D002648:Child; D002908:Chronic Disease; D004311:Double-Blind Method; D004415:Dyspepsia / Q000209:etiology / Q000517:prevention & control; D004751:Enteritis / Q000188:drug therapy* / Q000382:microbiology* / Q000503:physiopathology; D005260:Female; D005285:Fermentation / Q000187:drug effects; D005765:Gastrointestinal Agents / Q000737:chemistry / Q000627:therapeutic use*; D006801:Humans; D043183:Irritable Bowel Syndrome / Q000188:drug therapy / Q000382:microbiology / Q000503:physiopathology; D007792:Lactulose / Q000378:metabolism; D008297:Male; D008881:Migraine Disorders / Q000188:drug therapy / Q000382:microbiology / Q000503:physiopathology; D012294:Rifamycins / Q000737:chemistry / Q000627:therapeutic use*; D000078262:Rifaximin; D012720:Severity of Illness Index; D011795:Surveys and Questionnaires
D000900:Anti-Bacterial Agents; D005765:Gastrointestinal Agents; D012294:Rifamycins; D007792:Lactulose; D000078262:Rifaximin