Because of difficulties on recruiting participants

Recent study showed that SIBO is common among postgastrectomy patients and It appears to be associated with postprandial intestinal symptoms and might aggravate late hypoglycemia. SIBO could be a new therapeutic target for managing intestinal symptoms in postgastrectomy patients.The purpose of this study is to determine whether antiboitic (metronidazole) is effective in patients with postgasrectomy syndrome

Inclusion Criteria:

• age between 18 and 70
• gastrectomy for early gastric cancer with complete resection
• no reccurrence after follow up more than 6 months
• identified small bowel bacterial overgrowth by hydrogen breath test
• symptoms of postgastrectomy syndrome

Exclusion Criteria:

• hypersensive to metronidazole
• systemic chemotherapy history
• other organic gastrointestinal disease (inflammatory bowel disease, carcinoid syndrome, amyloidosis, intestinal obstruction)
• other gastrointestinal operation history except appendectomy, cholecystectomy)
• recent colonoscopic examination (within 30 days)
• uncontrolled psychopathy
• drug or alcohol abuser
• pregnant or breast feeding woman
• recent history of antibiotics treatment (within 90 days)
• recent history of PPI or H2 blocker treatment (within 30 dyas)
• recent history of probiotics treatment (within 30 dyas)
• recent history of prokinetics or antispasmotic treatment (within 15 days)
• severe systemic illness