It could be that your body was giving you hints, but you weren't paying attention. Think about it, anyhow.

I find that organic food can often be blamed for this. Last time it was 'natural, wild' blueberries. We have a tradition of having blueberry pancakes on Sunday morning. When I had diarrhea three Sundays in a a row about 7 pm, I threw away the blueberries and replaced them with bad, unnatural blueberries from the my local supermarket. No more diarrhea.

Did you take some Peptobismol? It really works.