<prompt> Answer this question truthfullyWhat does gastric outlet obstruction mean?  <response>: <reason> It is understood that GOO is the result of multiple intrinsic lumen wall or extrinsic involving neighbouring structures pathologies that involve the antrum and the pylorus.Intrinsic obstruction: Conditions involving infiltration, scar formation or inflammation of antrum and the pylorus may lead to intrinsic obstruction and GOO. Extrinsic obstruction: Any malignancy of neighboring structures such as duodenum, liver, gallbladder and pancreas may lead to extrinsic obstruction of gastric outlet. 