Starting Saturday night, my baby developed a fever (vomiting, diarrhea). I managed to bring the feve…

Starting Saturday night, my baby developed a fever (vomiting, diarrhea). I managed to bring the fever down yesterday afternoon, and it hasn't returned. She's been crying half the night, complaining of a stomach ache. She's already had a bowel movement (loose), but her stomach still hurts. My third little one just recovered from a nasty virus herself (she was sick for 2 days prior), and it was very tough. She was on IV fluids for 3 days, didn't eat anything for 3 days, and had frequent diarrhea and vomiting. However, she started receiving antibiotics on her first day in the hospital and recovered in 4 days. By yesterday afternoon, her stools were formed, and she was eating everything. My point is, my second baby hasn't been given antibiotics. They seem to have the exact same thing. Should I start giving her Meningo? Can I give it to her now? I'm taking my second one to the doctor tomorrow morning. What should I do now? I don't know how to relieve her pain.