Research plan and methodology Trial Design - A randomized controlled trial The trial will be executed in accordance with Good Clinical Practice guidelines Randomization - Patients with overt signs of acute upper GIB (melena, hematemesis, drop in haemoglobin with or without hypotension) are invited to participate in the trial. Investigators or research nurses approach patients and obtain their written consents. During endoscopy, if they have bleeding lesions suitable for standard endoscopic treatment and OTSC, the endoscopist then requests the next number sealed envelope to be opened by an endoscopy nurse. Patients are randomized to receive either standard endoscopic treatment (contact thermal methods or hemoclips with or without pre injection with diluted epinephrine), or the use of OTSC. Indications for endoscopic treatment are active bleeding (pulsatile or Forrest Ia bleeding, oozing from a visible vessel or a protuberance otherwise referred to as Forrest I b bleeding, or a non bleeding visible vessel or Forrest IIa lesion). Clots overlying bleeding lesions are irrigated or elevated using a cheese wiring technique with a minisnare. If a vessel is unveiled, randomization can then proceed and the assigned treatment is then carried out. The random number list is generated by computer software.