I have found that using Similac Advance Soy Formula for Infants, my son is alot less fussy, is able to spit up eaiser and has less gas then when I used other formulas trying to find the one that I liked. Leading up to the soy formula my son was angery, he was having massive gas issuse and was not able to get through the day with out some kind of horible outburst. Now that he has been on it for a while he is happy smillie baby, able to pas gas freely, and is able to regulate himself on how much he eats.