Figure.

Diagnostic criteria and breath test patterns according to the North American Consensus statement are shown. Diagnosis of hydrogen-predominant small intestinal bacterial overgrowth can be made via small bowel aspiration showing greater than 10³ cfu/mL or with breath testing that shows an early rise in hydrogen (blue line) of 20 parts per million (ppm) or more above baseline by 90 minutes (A). Intestinal methanogen overgrowth is defined as methane (red line) of 10 ppm or more at any point during the test (B). Flat-line pattern is defined as no methane and low fixed hydrogen production (low fixed hydrogen ≤3 ppm and no rise >1 ppm above baseline) (C). High baseline hydrogen is defined as baseline hydrogen greater than 20 ppm with no excessive methane (D). Normal breath test result (E).