Most studies of bloating have focused on functional factors, while data on organic abdominal distention are rare, and studies that combine small intestine bacterial overgrowth and/or oral cecum transit time abnormalities are more urgent to explore. On this basis, patients with functional abdominal distension complicated with small intestine bacterial overgrowth were divided according to whether there was abnormal oral cecum transit time, and given the same treatment plan. The relief effect of abdominal distension, small intestine bacterial overgrowth turning negative and oral cecum transit time recovery were observed, so as to further clarify the cause of abdominal distension patients.

Part 1 Clinical characteristics of small intestinal bacterial overgrowth in patients with abdominal distension of different etiologies The clinical characteristics of small intestine bacterial overgrowth and oral cecum transit time in patients with abdominal distention of different etiology (organic and functional) were studied to lay a foundation for further exploration of treatment of functional abdominal distention.

Part 2 Efficacy observation of functional abdominal distention combined with small intestine bacterial overgrowth To observe the effect of antibiotics on abdominal distension in patients with functional abdominal distension complicated with small intestine bacterial overgrowth, and observe the effect of rifaximin on small intestine bacterial overgrowth and oral cecum transit time, so as to provide new ideas for the diagnosis and treatment of abdominal distension patients.

Inclusion criteria:

Part 1 Clinical characteristics of small intestinal bacterial overgrowth in patients with abdominal distension of different etiologies

1. Age 18-60 years old and gender;
2. The chief complaint is abdominal distension and/or abdominal distension, abdominal distension and/or abdominal distension more prominent than other symptoms.

Part 2 Efficacy observation of functional abdominal distention combined with small intestine bacterial overgrowth

1. Patients with functional abdominal distension and small intestinal bacterial overgrowth were selected in Part 1;
2. No drug contraindications.

Exclusion criteria:

Part 1 Clinical characteristics of small intestinal bacterial overgrowth in patients with abdominal distension of different etiologies

1. Preparation for pregnancy, pregnancy, breastfeeding women, or overall poor compliance, or other conditions that the investigator believes need to be excluded;
2. History of malignant tumors, history of abdominal surgeries;
3. Food intolerance, confirmed or suspected lactose intolerance;
4. Diagnosis of urinary system (chronic kidney disease, etc.), immune system (scleroderma, etc.), nervous system (Parkinson's disease, etc.), mental system (depression, etc.) and other diseases outside the digestive system;
5. Antibiotics and microecological preparations should be used within two weeks. Use motility enhancers, secretagogues, antifoaming agents, spasmolytics, opioids, antidepressants and other medications within a week.

Part 2 Efficacy observation of functional abdominal distention combined with small intestine bacterial overgrowth

1. Antibiotics and microecological preparations should be used within two weeks;
2. Use motility enhancers, secretagogues, antifoaming agents, spasmolytics, opioids, antidepressants and other medications within a week.