I would have been suspicious of bms qod(every other day) in a bf infant
less than 4-6 weeks w/o documented weight gain. Except that a friend of
mine with her 4th baby had 3 bms the 1st week and gained but only stooled 1
x weekly for the first 8 WEEKS ! I was very worried the doc advised
suppositories, enemas, karo etc almost did a lower GI to r/o Hirshsprungs
disease (a condition that is a congental absence of innervation of the
colon) Oddly (or not) Hirshsprungs is often asymptomatic until solids or
formula are introduced to an exclusively Bf infant when an acute bowel
obstruction can occur, necessitating emergency GI
surgery and often a colostomy (temp). I have 2 friends: 45yo male who is
one of the first surviving post-op and his son 20 yo who had surgery while
I was a nursing student little did I know but I was observing another
miraculous benefit of Bf and mother's milk, the little guy got to grow for
7 months before he had to have surgery, a real bonus for his outcome and
recovery. Surgeons love it when the baby can grow before life threatening
revisions are necessary.

 I might add that another "common" cause of lack of stooling in the neonate
that often accompanies a meconium plug or ileus is cystic fibrosis, another
congenital condition that greatly benefits from exclusive Bf for as long as
symptoms allow.  I never take lack of a Bf baby stools in the early weeks
lightly even with growth I look for other signs that may point to a
potential concern.