What causes movement in the stomach?

The movement of food through the stomach and small intestine is called peristalsis. It is a series of involuntary muscle contractions that push the food along the digestive tract. Peristalsis is initiated by the presence of food in the stomach or intestine. The food stimulates the stretch receptors in the stomach and intestine wall, which send signals to the brain. The brain then sends signals back to the stomach and intestine wall, causing the muscle contractions to occur.

Peristalsis helps to mix the food with digestive juices, break down the food into smaller pieces, and propel the food along the digestive tract. It is an essential process for digestion and absorption of nutrients from food.