The 3 month child is normally exclusively breast fed in india.Such children are less likely to acquire bacterial or protozoal infection
through enteral route.The change of place usually does not cause infection unless the child is exposed to contaminated food or water or fed by unclean hands.
Most common cause of loose stools are intestinal viral infection which can be air borne also along with food and water.
Most of these infections do not require antibiotics or antiprotozoal unless superadded bacterial or protozoal infection is present.
The breast fed baby may have 15 motions per day which are thin and paste like and normal at this age.
So confirm again that stool is loose because of bacterial or protozoal infection. The two infections combined is less common phenomenon. This can be confirmed by stool examination done by a meticulous pathological evaluation of a fresh specimen of stool.with in 1 hour of passage of stool and culture for evaluation of a pathogenic organism. Depending on result a decision has to be made about use of antibiotic or anti protozoal or any other drug.
Till then give child Zinc liquid 10mg per day for 15 days(susp Zand D 1/2 ml per day)
and probiotic enterogermina
liquid 5 ml twice a day for 5 days.