Final answer:
The surgical procedure for the enlargement of the passage between the stomach's prepylorus and the duodenum is known as pyloroplasty.
Step-by-step explanation:
The surgical enlargement of the passage between the prepylorus of the stomach and the duodenum is called pyloroplasty. This procedure is indicated to alleviate conditions that block or narrow the pyloric sphincter, impeding the movement of food from the stomach to the duodenum. Pyloroplasty is one of several types of surgeries that may be performed on the stomach or the intestines, such as gastrostomy, duodenostomy, and enterostomy, each targeting different structures for different therapeutic reasons.