Quoting Toni A:" My little one is still BFing so last time he got sick we didn't have to worry too much about dehydration, ... [snip!] ... to the er, but I don't know what they are going to be able to do for you. They are unlikely to give a 13 month old medication. "
I agree that there's probably not a whole lot they can do for you right now. Typically stomach bugs only last about 24 hours. Sometimes you get unlucky, but most of the time it's gone as fast as it started. Recently my 2 year old had the stomach bug and he puked non-stop for about 8 hours. He couldn't keep water down.
What we did is basically covered us in towels (I got sick of changed every 5 seconds) with a cup of water or watered down apple juice next to us. He'd puke.. i'd have him take a sip or 2. Wait a half an hour, try to talk him into drinking more. Sometimes I'd use the straw to squeeze some juice or water in his mouth. Wait another half an hour and then try something solid. We didn't make it to the hour mark until he stopped puking.
Then all of the sudden he said he was hungry and drank the entire cup of juice and ate 2 pieces of bread.
Keep on top of the fluids. They do have the pedialyte freezer pops. In my experience, they hate the pedialyte because it tastes like salty juice. IMO, i wouldn't take LO in yet. The ER is filled with sick people this time of year. As long as she/he's peeing, she's most likely ok, just sick.