A mother walks into your pharmacy and wants you to recommend an over-the-counter product for her baby's symptoms of diarrhea. When you ask her for more information she tells you that her 4-month-old baby has had diarrhea for the past 10 hours. The baby also has a fever of 103 F (rectally). Everyone (mom, dad, older brother) also have been bothered with diarrhea. The baby has no known allergies and takes no medications on a regular basis. What would be the BEST recommendation for this parent?