Prevention of Recurrent Ulcer Bleeding in Patients With Idiopathic Gastroduodenal Ulcer

Inclusion Criteria: 1. Idiopathic gastroduodenal ulcer bleeding is defined as described in our previous studies \[12-15\]: Gastroduodenal ulcer bleeding is diagnosed based on: i. History of symptoms of upper gastrointestinal bleeding with endoscopically proven gastroduodenal ulcers; Idiopathic ulcer is diagnosed based on: i. No experience of ulcerogenic agents (e.g. aspirin, NSAIDs), or drugs of an unknown nature including traditional Chinese medicine during the 4 weeks before hospitalization of gastrointestinal bleeding episode; ii. Negative biopsy urease test and absence of H. pylori on histology in the absence of acid suppressive agents; and iii. No other cause of ulceration identified (e.g. hypergastrinaemia, Crohn's disease, cytomegalovirus and herpes infection). 2. Resume hemoglobin level which is same as or higher than the level prior to last ulcer bleeding episode or stable hemoglobin level (drop \<2g/dL) within one year prior randomization iii.3. No reported gastroduodenal ulcer or ulcer bleeding from last upper endoscopy 2.4. Aged 18 years old or above. 3.5. Written informed consent obtained. Fingerprint of subject with a witness involved in the consent procedure will be accepted for illiterate subjects. Exclusion Criteria: Patients will be excluded from the study if they have any of the followings: 1. Concomitant anticoagulant 2. Concomitant use of NSAIDs, aspirin or COX2 inhibitors 3. Previous gastric surgery 4. Requirement of maintenance PPI (e.g. reflux esophagitis) 5. Advanced comorbid conditions (defined as American Society of Anesthesiologists grade 4 or above) or active malignancy 6. Subjects who are or will be pregnant or lactating 7. Subjects who have known hypersensitivity or allergies to any component of misoprostol and lansoprazole. 8. Subject who has current or historical evidence of hypergastrinaemia syndrome or other hypersecretory condition.