Omnicef and uti

My 2 1/2 yr odl was put on Omnicef over a week ago for a severe ear infection in both ears and a UTI caused by her "holding" her stools ( she doesnt like to poop) Well she usally has painful bm's caused by IBS (yes toddlers can have IBS) But i noticed tonight that her stool, which was still large and painful was stained red... parts of the stool were COMPLEATLY red... i almost rushed her to the ER.. but first i looked up bloody stools in toddlers and discovered that Omnicef caused a Infection in the intestinal Tract and can cause bloody stools, or orange tinged stool... She hasnt really had much other side effects, other then a little irratablity.. but i dont think we will be going with Omnicef again....