Hi--
I'd bet money he's allergic to the formula you're giving him. At his age he should be having a bowel movement EVERY time you feed him. The fact that he isn't going on screams food allergy to me (both my boys have them, so I'm a bit of an expert on this one). I say change his formula. Ideally, you could make your own formula. There are recipes all over the web for this, or I can help you if you like. You want to stay away from all dairy, including casein and whey protein, and I would also stay away from soy. All soy, unless it is organic, is genetically modified and not good for you. Add that is is high in phyto-estrogens (chemicals that act like the hormone estrogen in the body) and it can really mess up his hormonal balance. Goat's milk is considered a good alternative, and you can get it through Vitamin Cottage (there's one up here in Castle Rock). You could also try getting your milk back--it's possible, but difficult. I think your best option is making your own formula--it's even cheaper then the powdered stuff, and a lot healthier. I'm only up the highway from you if you'd like help. My girlfriend just went through this with her niece, so I can get all the research from her for you. OR you can call her yourself---I know she wouldn't mind. She's a biochemist and an expert in nutrition as well, so she'd really be able to help. Let me know if you'd like our help.
J.