Small intestinal bacterial overgrowth (SIBO) denotes an increase in the concentration of bacterial population in small intestine. There are several mechanisms such as acid secretion in the stomach, motility of gastrointestinal tract and immune response which prevent overgrowth of bacteria in healthy individuals. Breakdown of this mechanism predisposes to the development of SIBO.  Conditions associated with increased risk of SIBO include  diabetes mellitus, intestinal strictures and blind loops, post gastrectomy status, gastrointestinal dysmotility, chronic opioid or proton pump inhibitor use, immune deficiency states, etc.  Usual symptoms of SIBO are non-specific and include bloating, diarrhoea and flatulence. Quantitative culture of duodenal/jejunal aspirate is the gold standard test for diagnosing SIBO. Breath tests are alternative diagnostic tools and are more frequently used in clinical practice due to their simplicity and non-invasive nature but are not very accurate. Recent developments such as availability of next generation sequencing and capsule breath test devices to diagnose SIBO appear promising for clinical application in future. Treatment of SIBO includes a short course of antibiotics, correction of nutritional deficiencies and treatment of predisposing factors. This review discusses the risk factors and clinical features of SIBO and provides an update on the diagnostic tests and management.