How fast can food pass through the body?

Food takes many hours to pass through the body, though I believe the exact amount of time depends on the particular food. What you’re describing may be the peristaltic wave (basically, your body’s response to eating being to get rid of the old to make room for the new).

Most casual references say 48 hours for normal progression. You can always eat some corn and then time it.

I have had mild cases of food poisoning that begin the process of expelling the material immediately (before the end of the meal)- how long it would take under those conditions for a particular particle of food to complete the trip, I don’t know. From the effects, I was say not very damn long.

Meat can take weeks to completely leave the body. Everything else 24 to 48 hours on average.

I swallowed one of those medical camera capsules about half the size of your thunb it took only
3 to 4 hours to pass through my system.