Explanation

In the process of digestion and absorption, masticated food (bolus) enters into oesophagus and is pushed further into the stomach by involuntary muscle movements. This involuntary muscle movement is responsible for food transfer from food pipe to rectum and is called peristalsis. The muscular coat of alimentary ($II^{nd}$ from outside and $III^{rd}$ from lumen) is composed of outer longitudinal and inner circular muscle fibres. Both muscle fibres of muscularis (unstriped or smooth) are responsible for peristalsis. Between these two muscle fibres of muscular coat, a network of nerve fibre is present, which is known as plexus of auerbach, (controls peristalsis)