Peristalsis

Peristalsis explained in an easy to understand way:

Imagine trying to squeeze the last bit of toothpaste out of a nearly empty tube. Just as you apply pressure and create a wave-like motion with your fingers to move the toothpaste forward, your digestive tract uses a similar method called peristalsis to push food along. In both cases, a coordinated series of muscle contractions work like a gentle, rhythmic push to move contents from one end to the other, ensuring nothing gets left behind.