Can old yogurt be eaten after it has expired?

You can drink it. Yogurt itself is made of fermented milk. The shelf life mentioned by the manufacturer actually means that it will maintain the best taste before use. But even if it is overdue, it doesn't matter if the milk is fermented for two days. In fact, you should be able to find that it just tastes sour and tastes worse than before. Don't eat if you are afraid of diarrhea, but normally yogurt won't have diarrhea.