The organ that pushes solid waste through it is the large intestine.

Here's a breakdown:

* Small intestine: This is where most digestion and absorption of nutrients occurs.

* Large intestine (colon): This is where water is absorbed from the remaining waste, and the waste is formed into solid stool. The muscles in the large intestine contract (peristalsis) to move the stool along.

* Rectum: The last part of the large intestine, where the stool is stored until it is ready to be expelled.

* Anus: The opening at the end of the rectum through which waste is eliminated.