From June 2021 to December 2021, patients with gastrointestinal discomfort (including abdominal pain, bloating, belching, dyspepsia, constipation, diarrhea, nausea and loss of appetite) from the Sixth Medical Center of the PLA General Hospital were enrolled in this study. The lactulose hydrogen-methane breath test was used to diagnose SIBO. All patients had an abdominal ultrasound as well as laboratory tests on the same day that they had the breath test. Patients were divided into GBPs group and control group according to whether GBPs were found under ultrasound. This study was conducted in accordance with the Declaration of Helsinki and approved by the Ethics Committee of the Sixth Medical Center of PLA General Hospital. Written informed consent was obtained from all subjects.