the answer is social skills :)
Are you ok? The answer to your question is at most 10 days
The journey begins soon as you take a bite out of the sandwhich. your sliva starts to get heaver. You start chewing it and it goes down your esphoquist. Then down into your stomach. Your gut starts to work to get all the nutrinous from it. Then the waste. you know what happens to the waste. You use the restroom ( this is not meant to be funny take this sersouliy).
you can use this information to make it 3 paraghrpahs long put little deatails that matter into it.