<prompt> Refractory gastric ulcer is defined as.Ulcer that fails to heal despite 4 weeks of regular proper dose PPIUlcer that fails to heal despite 8 weeks of regular proper dose PPIUlcer that fails to heal despite 12 weeks of regular proper dose PPIUlcer that fails to heal despite 16 weeks of regular proper dose PPI  <response>: Refractory gastric ulcer - Fails to heal by 3 month of regular proper dose PPI Reason could be - Zollinger Ellison syndrome Refractory Duodenal Ulcer : 8 weeks with regular PPI Treatment Refractory Gastric Ulcer : 12 weeks 