Final answer:
Pyloroplasty is the surgical enlargement of the passage between the prepylorus of the stomach and the duodenum, typically performed to alleviate conditions that impair the movement of chyme from the stomach to the intestine.
Step-by-step explanation:
The surgical enlargement of the passage between the prepylorus of the stomach and the duodenum is called a pyloroplasty. This procedure is intended to widen the outlet of the pyloric region to facilitate easier passage of contents from the stomach to the duodenum. In cases where there is a blockage or narrowing at the pylorus, possibly due to ulcers or scarring, a pyloroplasty can help to alleviate symptoms by expanding the pyloric canal.
During a pyloroplasty, the surgeon makes an incision in the longitudinal and circular muscles of the pylorus, which is then sutured in a way that leaves the pyloric channel wider than before. This allows the chyme - the mixture of partially digested food and digestive juices - to pass more freely from the stomach to the duodenum for further digestion.