胃切除术（gastrectomy）为胃的一部分或全部的切除手术治疗法。除了胃肿瘤以外，主要还是针对胃溃疡、胃损伤等病症所行使的医疗行为。

胃切除术是要进行全身麻醉的手术、切除范围大致分为胃的部分切除和全部切除。通常在手术时、出血量并不多、就手术而言是一种中规模的手术、输血的必要性也比较少。就我们知道手术后会出现一些特有症状的毛病、称之为胃切除后症候群。而近年来腹腔镜手术也逐渐被采用。

A gastrectomy is a partial or total surgical removal of the stomach.

Gastrectomies are performed to treat stomach cancer and perforations of the stomach wall.

In severe duodenal ulcers it may be necessary to remove the lower portion of the stomach called the pylorus and the upper portion of the small intestine called the duodenum. If there is a sufficient portion of the upper duodenum remaining a Billroth I procedure is performed, where the remaining portion of the stomach is reattached to the duodenum before the bile duct and the duct of the pancreas. If the stomach cannot be reattached to the duodenum a Billroth II is performed, where the remaining portion of the duodenum is sealed off, a hole is cut into the next section of the small intestine called the jejunum and the stomach is reattached at this hole. As the pylorus is used to grind food and slowly release the food into the small intestine, removal of the pylorus can cause food to move into the small intestine faster than normal, leading to gastric dumping syndrome.