Baby not pooping as much. Upset stomach

I have a seven week old baby family and I just transitioned from breast-feeding to formula and I noticed he’s only pooping maybe twice a day now versus 7+. Hey seems to have an upset stomach and pain and very gassy. I think giving him gas drops with every feeding and he is on Enfamil gentle ease which is supposed to help with gas and upset stomach. Have any of you experience this and what else can I do?