Hi libby welcome to the board.
From your post I am assuming that you received holsteins or another dairy breed. I had a similar problem with scours with the two holstein heifers I have. I made the mistake of giving them replacer the night I brought them home, instead of electrolytes. Mine came from a dairy and were bottle fed, but they were given milk so the change to replacer was hard on them. It took two weeks for them to get over the scours then. I tried everything I was told to try and everything I read on this board, except the bleach.
In the end what seemed to work was double doses of pepto 2-3 times a day, yogurt and small amounts of hay. I don't know if this combination really worked or not or if they just finally adjusted to the replacer and the calf starter. I feed Vigortone 22NT so I know replacer quality wasn't an issue. Oh, don't forget to give them electrolytes, it is extremely important to keep these little guys hydrated. The yogurt is to put the "good bugs" back in there stomach.
I am new to this board and cattle also, so I am definately not an expert, but hope maybe this little bit of info will help.