Your stomach has a strict bouncer at the exit

The stomach turns a meal into a manageable stream

Before food can move onward, the stomach mixes it with digestive juices and churns it into chyme, a soupy mixture of partly digested food. Waves of muscle contractions push this mixture toward the pylorus, but the opening is narrow. Larger pieces are swept back into the stomach for more grinding rather than passing straight through.

That back-and-forth action helps make what leaves the stomach easier for the small intestine to handle. The pylorus is not making conscious choices; its opening and the stomach’s contractions are coordinated by nerves and hormones.

The intestine can slow the handoff

The small intestine does more than receive whatever the stomach sends. As chyme enters its first section, the duodenum, signals from the intestine can slow stomach emptying. A meal rich in fat, for example, tends to prompt a slower handoff, giving the intestine more time to process what has arrived. The stomach’s pace therefore responds to conditions downstream, not just to how full it is.

This is why a meal does not simply pour into the intestine all at once. The stomach meters out food while the intestine signals how quickly it can take more. The result is a coordinated handoff: the stomach keeps mixing and reducing the meal as the small intestine processes each incoming portion.