Should I take him in?

My son is 21mo and I believe he has the stomach flu. He's had it a little over 24hrs. He hasnt puked but he has diarrhea really bad. I've gone through 18-22 diapers since 7 last night. I've been giving him water and Gatorade. He's lethargic. I can't get ahold of his pedi :/ should I take him to the er and be looked at or just keep giving him fluids. He's never been dehydrated before so idk what's safe or unsafe. Thank you!

If he's lethargic take him in.

I would take him in

If he's lethargic then yes absolutely take him in.
Feel his soft spot, is it sunken in?

Quoting Nathaniel'sMom:" If he's lethargic take him in."

I agree OP!
If you hadn't mentioned this I would say don't worry too much... but if he's lethargic at all he needs to be seen by a dr. Good luck, hope he feels better soon!!!

Lethargic as in he's just super tired and slept more than normal. I'm just gonna take him in just in case.

Take him in. Better safe than sorry!