I don't know where the idea comes from that it is only after 6 weeks
that exclusively breastfed babies' stools may become infrequent.  I
think it can occur much earlier, by three or even two weeks.  The
issue is that before this, infrequent stools *usually* mean inadequate
intake, but not always.  Watch the baby breastfeed.  If he is
breastfeeding well (open-pause-close type of suck for several
minutes), there is no need to be concerned about the bowel movements
as long as they are soft and yellow, whatever his age.

Jack Newman, MD, FRCPC