My cycling buddy is a gastroenterologist and he tells me some amazing stuff about the human intestinal tract.
At any one time about 10 litres of the water in your body is involved in the digestive cycle; the stomach mashes it all up and adds water, the enzymes are added and off it goes to the small intestine where the nutrients are absorbed then on to the large bowel where the water is recovered. If the contents are contaminated with a nasty, the large bowel just says “no thanks” and on it all goes, straight for the bog. Or your pants if you’re unlucky. You can live without your large bowel but it’s not very pleasant.
And yes, worst food poisoning I ever had was from hotel ice cream in Pakistan and I couldn’t believe how much liquid came out of both ends of my body.