You continue coartesian as adivised by your doctor and the loose stools are due to antibiotic clavam. Continue antibiotic as advised by your doctor for infection and you can add probiotic
or saccharomyces sachets as these will take care of antibiotic associated loose stools and continue calpol
for fever and to prevent dehydration
you can give oral rehydrating solutions. If you feel any problem make a follow up visit with your doctor.