Answer: Myth

The major part of the digestive process takes place in the small intestine. The stomach takes in the food, then churns it and breaks it into tiny particles called “chyme.” The chyme is then released in small batches into the small intestine, where most digestion occurs. Contrary to popular belief, foods do not digest in the order they are eaten. Everything lands in the stomach where it’s all churned together, and only when it’s ready is it released into the small intestines together.

Source: https://www.webmd.com/women/features/stomach-problems#4