Any one can share and give review on formula milk? Which brand is more favorable to baby?

[newlife171112]

Im giving my 10 weeks boy Frisolac although he don have problem to poo but encounter wind and gas issue, most of the time when he drink Friso he tend to strain alot and receny the amount he drink jas been reduced and he refuse to drink more milk and wanted plain water.
i just switch to Nan 1 pro few days ago the gas issue improved but he having constipation and the poo is dark green color. Did anyone having the same problem with nan 1pro?