what pandora said. My DS had the same problem. Does your bub 'burp' well?? My DS had trouble with wind, instead of it coming up, it went through him which seemed to cause problems with him not only passing the wind but also his bowel movements (my DS is breast fed). Wind drops helped, but really the problem just got better as his body matured & he started working it through on his own..... kicking his legs & squirming etc.

HTH