After a partial gastrectomy or pyloroplasty, clinical manifestations that include increased pulse, hypotension, weakness, pallor, sweating, and dizziness are a result of

I think they area as a result of a rapid gastric emptying and creation of high osmotic gradient in the small intestine that causes a sudden shift of fluid from the blood vessels to the intestinal lumen. Gastrectomy is the removal of part or all of the stomach. A partial gastrectomy involves the removal of a part of the stomach, the lower half is removed mostly, while full gastrectomy involves the removal of the entire stomach.