Is it normal to have to poop after anything u eat immediately?

Gastrocolic reflex: There is what's called a gastrocolic reflex that starts when you eat something, the stretch of the stomach walls stimulate mechanicoreceptors that stimulate your sigmoid colon to contract and starts a chainreaction that leads to the urge to defecate. Some relate an overactivity of this reflex to irritable bowel syndrome.

Gastrocolic reflex.: The gastrocolic reflex stimulates large intestinal contractions when food enters the stomach - helps us move our bowels, as more waste is on the way from above. Some people have a very brisk gastrocolic reflex wherein they have to move their bowels right after they eat, sometimes even in the middle of their meals. Not abnormal, but mention it to your usual doctor just to have it on record.