help!

Ye

my 1 year old bby girl has been having diarrhea for 3days now. I took her yesterday to the Dr and he told us that she should be getting better within 24-48 hours (Stomach flu). anyways she's no longer throwing up she just has diarrhea and it's yellow. and not as runny as the first two days. what can I give her to stop it or what's going on. I feel so lost! FTM😣 Thanks in advanced