He’s 5 had gastro twice and lasted about 4-5 days sometimes a week but his appetite didn’t fully pick up until like 2w later he was sipping and nibbling until then. Because you said he IS sipping and nibbling (as opposed to a toddler not having anything) he was sent home. No it’s not ideal we get worried but they’ll get by and survive w that. Try Hydralyte popsicles they’ll think they’re having an icy pole but it’s loaded w electrolytes, or buy vitamin water powder and make that into popsicles. My boy ate like 5 of those a day when he had gastro coz everything he tried to eat, came back up (or out). And no appetite. But at least he was getting something in 😏
Can’t say for sure but when our boy had horrendous diarrhoea after his one year jabs they said they would only be concerned if it went on beyond 10 days.