Ate bad toast: diarrhea 24 hours later – connection?

Hi, as I mentioned in the title, I ate what I suspect was some spoiled toast. The package had been open for a while, and the toast had a very sour taste, like fruit was fermenting. However, since I couldn't see any mold, and Google assured me that this can happen, but that the toast was still edible, I ate it. Two slices. Afterward, the whole thing seemed a bit unsafe, so I threw the rest away.

Now, almost exactly 24 hours later, I have severe diarrhea and an upset stomach. Could this be from the toast, or could it have happened earlier?

Thanks for your answers!