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Overview of your stomach & bowel

Illustration of the human digestive system showing salivary glands, oesophagus, liver, stomach, gall bladder, pancreas, small & large intestines, appendix, rectum & anus.Your digestive system is like a tube that starts at your mouth, goes through your body, and ends at your anus (bottom). It's the part of your body that digests and absorbs your food and passes out any solid waste as faeces, or poos. It can take anywhere from 12 to 48 hours for food to pass through your digestive system, depending on what it is.

Your liver and pancreas are attached to your digestive system by small tubes. Your liver makes bile, which is initially stored in your gallbladder. Your pancreas makes the enzymes that help your digestive system break down food. Your pancreas also produces the hormone insulin which controls blood glucose (sugar).

You start digesting food in your mouth by chewing it. It then travels down your oesophagus (or food pipe) into your stomach. A tight band of muscle at the top of your stomach works like a valve to stop food and acid flowing back up. Sometimes this doesn't work properly, causing acid reflux and indigestion.

Your stomach produces acid and its muscular walls contract to break up and digest your food. The food then passes through your small bowel (also called your small intestine). The surface of your small intestine has lots of folds, creating a very large area through which nutrients can pass into your bloodstream.

At the end of your small intestine, the liquid waste passes into your large intestine (also called your colon, or large bowel). The large intestine reabsorbs much of the fluid and pushes the solid waste into your rectum, where it's stored until you're ready to go to the toilet. It then passes out through your anus.

Written by HealthInfo clinical advisers. Last reviewed July 2021.


Page reference: 372989

Review key: HISTB-38551