###Human: My 6-month-old baby gets diarrhea on taking new formula milk. Why does it happen? ###Assistant: Hello. I appreciate your concern regarding your child. I would like to advise that transition can cause diarrhea but it should settle within four to five days. If it does not then we should change the feed. Ensure hydration, give him ORS (oral rehydration solution) solution (dissolved one packet in one liter of water). She must take 90 ml of this solution after each loose stool. This ORS contains electrolytes that have lost by stool. Give it until loose stool subsides. Syrup Zinc 5 ml once a day for 14 days, it will fulfill zinc deficiency in your child and prevent further episodes of diarrhea and pneumonia also. Give him semi-solid food more along with curd (this will help to improve the digestion). During this illness watch for any color change in urine output or decreased urine output, and any lethargy. In case they come please consult.