Natalie is 14 weeks and she's been through a bunch of different "poop phases." First she'd save it all up for one MAJOR poop a day and maybe a couple small ones. The big ones were enough that often not only would Natalie need a change of clothes, so would DH
AND I. :shock: And as often as not, it would happen in the middle of the night and keep us all up a couple hours.
THEN she went through a phase, only just recently ended, where she pooped after EVERY feed.
NOW she's pooping usually after her first two feeds of the day, maybe another one later on.
Odds are a baby won't have trouble with mother's milk per se; however, if he's lactose intolerant and you're consuming any dairy products that will be in your milk, that WILL affect your baby.
If you're concerned about gas, you can try giving Mylicon before each feed. You can also check your diet for any other possible gas-causing culprits, like cabbage, broccoli, cauliflower, and in some cases, tomatoes or peppers. Some babies also react to wheat and/or soy and/or egg. You can check the Food Allergies forum for more specifics.
Good luck - hope this gives you a place to start!