At every stage of digestion, food is pushed through the system by a powerful muscle action called peristalsis. The muscles lining the intestine contract then relax in a rhythmic, wave-like action. As the intestine walls are squeezed together, the food is forced further along the tube.
The job of your large intestine is to absorb water, minerals, and some of the remaining nutrients from your food. It will change the leftover waste into a bowel movement. This is also called stool. Your rectum stores the stool until you feel the need to have a bowel movement. Muscles of your rectum then push the stool through your anus and out of your body.
It takes about 36 hours for food to move through the entire colon. All in all, the whole process — from the time you swallow food to the time it leaves your body as feces — takes about two to five days, depending on the individual.
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