Maximum speed of food through the body?

WARNING! This post has mucho ickiness!

Earlier this evening I went to a buffet with 5 other family members, none of which experienced any difficulties. I, however, did not fare so well. By the time I returned home (approximately an hour and a half after we began eating, and maybe half an hour after finishing) I was experiencing major intestinal cramps. I made it to the bathroom and commenced what could euphemistically be termed “explosive decompression.” This was far and away the most voluminous episode of its kind I have ever experienced, and it was repeated to a considerably lesser degree three more times in the next couple hours.

The odd thing is that on my second trip to the small room, I noticed that a leaf of lettuce had remained unflushed from my first trip. I always start a buffet with a salad to make me feel less guilty over the next couple of plates, and the last time I had eaten any lettuce was supper the night before last. I find it a stretch to believe that the lettuce I saw was two days old, yet I am likewise rather astonished that it could make its way all through my system in under two hours! Isn’t there something like 50 feet of intestine it would have to navigate before finding its way to its final destination? How long does it take for input to become output normally, and what’s the speed record for extreme circumstances?

I can tell you I have seen it nearly break the sound barrier - but this was food going in reverse due to too much drink, BBQ, and rough seas.

warning this is also gross

when i was about 15, i had a horrendous stomach bug that flattened me for a good few days.
during this time, all i ate was the universally therapeutic chicken soup.
on the fourth day i felt a little better and by the evening i was craving some solids. my mum (bless!) made me some oven chips (that’s french fries to you merkins out there) which i made short shrift of.
about 2 hours later i had to literally sprint to the bathroom.
i got there just in time.
inspecting the bowl contents, as you do, i was amazed to see not fecal matter as such, but chips. fully recognisable, including, i swear, teeth marks.