Evacuation Dysfunction Does Not Impact Breath Test Results

Area of Science:

• Gastroenterology
• Microbiome Research
• Diagnostic Testing

Background:

• Evacuation dysfunction impacts gastrointestinal motility, but its effect on small bowel microbiota is not well understood.
• Comparing breath test outcomes in patients with and without evacuation dysfunction is crucial for understanding SIBO diagnosis.

Purpose of the Study:

• To compare glucose breath test (GBT) and lactulose breath test (LBT) outcomes in patients with and without evacuation dysfunction.
• To evaluate the diagnostic utility of high-resolution anorectal manometry (HR-ARM) and balloon expulsion test (BET) in identifying causes of abdominal bloating.

Main Methods:

• Retrospective review of 344 patients undergoing GBT and 144 undergoing LBT between 2018 and 2024.
• Assessment of evacuation dysfunction using HR-ARM and BET.
• Comparison of breath test results based on HR-ARM and BET findings.

Main Results:

• Abnormal BET was found in 53% of patients; breath test abnormality rates were similar regardless of BET results.
• Patients with positive vs. negative breath tests showed similar anorectal pressures, rectal sensory function, and BET results.
• LBT showed significantly higher rates of small intestinal bacterial overgrowth (SIBO) compared to GBT (20.1% vs. 7.6% for SIBO only).

Conclusions:

• Evacuation dysfunction does not influence breath test outcomes for SIBO.
• HR-ARM and BET are effective in diagnosing the etiology of abdominal bloating in chronic constipation or IBS without diarrhea.
• The diagnostic yield of hydrogen breath tests, particularly LBT, in this population requires further investigation regarding specificity and sensitivity.