<prompt> Zollinger-Ellison syndrome is characterized by all of the following except -Post bulbar ulcerRecurrent duodenal ulcerSevere diarrheaMassive HCL in response to histamine injection  <response>: Important points that should raise the possibility of ZES in patients with duodenal ulcer.ulcers in unusual locations i.e. postbulbar ulcersrecurrent or refractory ulcersulcers with diarrhoeamultiple ulcersulcers associated with prominent gastric foldsulcers with findings so MEN-1 endocrinopathy, family history of ulcer or endocrinopathy, nephrolithiasisulcers without H. pylori infection 