The role of Helicobacter pylori infection in functional dyspepsia remains controversial. Several randomized controlled trials in western countries have shown no significant advantage over placebo. But some recent studies in Asian population were different compared to the result of studies in the Western population. At the present time, it seems to be difficult to conclude the efficacy of the H.pylori eradication therapy in patients with H. pylori-infected functional dyspepsia.

The investigators hypothesize that eradication of Helicobacter pylori has a sustained global symptom improvement in patients with H. pylori infected functional dyspepsia.

Functional dyspepsia: diagnosed by Rome III criteria of Functional gastrointestinal disorder Treatment regimen: Combination of proton pump inhibitor, Amoxicillin, Clarithromycin for 7 days Placebo: Same shaped placebo drugs

Inclusion Criteria:

• Functional dyspepsia by Rome III criteria
• Normal endoscopic findings
• H. pylori positive by Urea breath test

Exclusion Criteria:

• Patients with severe concomitant systemic disease
• Patients with GI surgery
• Females with pregnancy or breast-feeding
• Irritable bowel syndrome, inflammatory bowel disease
• Duodenal Ulcer, Gastric Ulcer, GI bleeding
• History of eradication therapy of Helicobacter pylori
• Malignancy
• Psychosomatic disease