How the bowel works

The mouth, oesophagus, stomach, small intestine and the large intestine or colon are all part of the digestive system.

(Image from Norgine)

The digestive system works by pushing food through the intestines which usually takes between 24 to 72 hours. Muscular contractions squeeze (peristalsis) the food through the different sections of the intestine. These different sections are separated by bands of muscles, or sphincters, which act as valves.

The passage of food from one area of the intestines to another is coordinated so that food stays in a specific area for long enough for the gut to do a particular job—absorb fluids and nutrients, or process and expel waste.