Hi, I had gone through your question and understand your concerns A child suffering from cold, and fever , presenting with lose motions after taking medicines , two reasons can be for this 1.Disease itself which caused cough, fever can have additional symptom loose motions although it was not present earlier. 2. Antibiotics can also cause diarrhoea as a side effect , more common with amoxycillin group of antibiotics. You have not mentioned what antibiotics your baby is taking. Now on treatment part :- pre-probiotics can be added , ORS to be given to prevent and treat dehydration. Decision may be taken to change antibiotics if diarrhoea is severe enough , usually change of antibiotics not required. So keep hydration of your baby , give ORS , and Pre-probiotics and keep watch on danger signs like dullness, poor oral acceptance , decrease urine, high fever, rapid breathing , and continue treatment as prescribed by your doctor . Hope this answers your question. If you have additional questions then please do not hesitate in writing to us. Wishing your kid good health.