Baby Gas

So I exclusively pump (trust me I wouldn't if I could but please don't give me crap about how I should try a lactation consultant) and my baby has really bad gas. It doesn't seem to matter what I eat he always has gas after eating so I don't think it's something in my diet. We give him gripe water sometimes. I was wondering what bottles work really well for helping with gas I already used the mendala and the avent bottles