Loose motion in 6 month baby. Motion?

My son was exclusively breastfed till 6 months..was planning to introduce solids after 6 months completed..but 1 week before 6 months could complete..he started having loose motion..his poop was green,frothy and watery..and his poop count was 6 to 7 times a day..he was active..doctor gave him g-norm,zinc solution and OFM suspension..slowly loose motion was coming under control..when suddenly he caught a cold..he had cough,sneezing and a runny nose..so I had to take him to the doctor again..Doctor prescribed levocetrizine drops..used it for 2 days..immediately he started going green and watery again..doctor gave cefixime suspension for 3 days but it still did not stop...Finally I stopped all the medicines after 2 weeks..was not able to starts solids because of this motion..finally started cerelac wheat..but still when I feed him milk he goes in green..sometimes after cerelac he goes in yellow..still his poop count is 6 times a day..what can be given to stop this loose motion?