Arlesheim

Hydrogen (H2) breath tests are used to detect problems with digesting carbohydrates like lactose and fructose, measure how quickly food moves through the intestines, link hydrogen gas production to symptoms such as bloating and diarrhea, and diagnose small intestinal bacterial overgrowth (SIBO). Differentiating between carbohydrate intolerance and SIBO is important because they require different treatments—diet changes for intolerance and antibiotics for SIBO. However, breath tests alone may not always accurately diagnose SIBO due to variability in measuring transit time, which can be improved by combining breath tests with imaging methods to confirm intestinal transit. This study evaluates a new, simple, and affordable method that combines a 20g lactulose hydrogen breath test with abdominal X-ray imaging to assess oro-cecal transit time, SIBO, and carbohydrate intolerance. The approach involves taking an X-ray when hydrogen levels rise during the test to check if contrast has reached the cecum. If the contrast is not visible when hydrogen rises, SIBO may be present; if it is visible, normal transit is confirmed and symptoms after this point suggest carbohydrate intolerance. Participants referred for breath testing from 2020 to 2024 will have data from the combined test analyzed retrospectively. Researchers will assess the safety and practicality of this combined test and how well it identifies digestive issues. The study measures include the timing of hydrogen production and imaging findings during the 3-hour test period. If successful, this method could improve diagnosis and treatment decisions for digestive problems.