Any excess fluid travels to the large intestine where the body reabsorbs it (or it’s absorbed by fibre), increasing the bulk of your stool. This is why hydration is so important as it reduces the risk of constipation.
Undigested food and waste products are then carried by peristalsis (muscular contractions) along to the large intestine. Here’s where the magic happens, bacteria ferment undigested food, mostly fibre, and produce beneficial compounds such as short chain fatty acids and vitamins and have a good old sort out of waste. Clever little things!!!
After all this hard work, your large intestine will make one mass movement to expel a stool, which is made up of essential waste products and bacteria. Ta da!