Why do I poop IMMEDIATELY after drinking coffee? ?

You don't poop because it's a stimulant. There is natural caffeine in coffee, but there is also a natural laxative in coffee beans. There's nothing wrong with you. You don't have a sensitive stomach. Some people react differently to different chemicals in their bodies. Any time I eat eggs or fish, about an hour later I practically **** my pants. It's just the way your body is wired dude.