What could this be?

I know everyone is gonna tell me to go see a doctor, well I’m already at urgent care waiting to get seen but it’s taking forever so i want to know if anyone else’s LO has ever experienced this and what it could be. So me and my ex share custody of our 22 month old. He had him Monday-Wednesday when I got him back yesterday his dad told me “he’s been having diarrhea since Monday, and he’s got a really bad diaper rash and won’t eat anything.” So I started freaking out, googling shit, was pissed at him for not telling me but my mom who’s a nurse told me if it keeps going today to take him to urgent care. He’s had around 12 diarrhea diapers in 24 hours, but hasn’t ate anything. I don’t think this is normal, also he doesn’t have a fever he’s only threw up once.. I don’t think it’s the flu.