Omnicef and urinary tract infection

My 12mo old daughter began taking Omnicef two days ago for a urinary tract infection. She's normally a very happy child who takes about 4oz of milk and then crashes for the night. Both nights since starting Omnicef she has been extremely restless and doesn't want to sleep. When you hold her she wants down, when you put her down she wants you to pick her up and cries constantly. The only way to get her to sleep is to take a ride in the car....and then pray she doesn't wake up when we're bringing her back into the house. The red-ish colored stool happened after the first dose as well. She had one when she woke up the next morning and another a few hours later. These were the worst diapers I've ever seen. We're stopping the doses and consulting her pediatrician. Hope this helps.