Summary: Small intestinal bacterial overgrowth (SIBO) can be characterized by the excessive growth of selected microorganisms within the small intestine with a wide spectrum of gastrointestinal symptoms. Currently a bacterial concentration of above 103 CFU/ml in a duodenal/jejunal aspirate is generally considered diagnostic of SIBO. Symptoms of SIBO can include, but may not be limited to, nausea, bloating, flatulence, abdominal distention, abdominal pain, diarrhea and/or constipation. Multiple independent risk factors have been identified for SIBO, including small bowel anatomic alteration and dysmotility irrespective of the cause, hypo- or achlorhydria and local or systemic immunodeficiencies. Although subject to debate and controversy, glucose or lactulose breath tests have become the diagnostic method in clinical practice due to their noninvasive nature and low cost. Broad-spectrum antibiotics are the first line treatment for SIBO, however, the number of studies on their efficacy in children is limited.