<<,a 4 month old called (she lives 1700 miles away in my old hometown).  Her
baby boy has only pooped on his own, three times in the last six weeks. >>
You did not say how often mother is using these other methods to get the baby
to stool.  Also what did the stool look like and how much was there.  My
understanding  is that in congenital megacolin and Hirschsprung's the bowel
does not empty because of peristaltic activity in the involved segment.  The
bowel enlarges (dilates) due to the trapped stool.  Often the baby will have
liquid stool around the obstruction.  The baby is constipated, abdomen becomes
distended and finally vomiting occurs because of the obstruction, the bowel
can't take anymore.   I think congenital megacolin runs in some families--my
brother-in law had it.
I mention all this because:
1.  Parents get upset if baby doesn't stool every day and tend to overreact.
2.  I have had  at least one baby who had one massive stool every 17 days well
into his second year.  The baby was being given prune juice with maltsuprex
daily and suppositories every 3 days until mom came for help from an LC.  She
finally drew the line at enemas.  I have seen many others who go almost as
long.  To me when a baby is PAST 6 weeks of age, is still urinating about the
same and the stools remain soft; there isn't a problem.
3.  I would hate to see this baby go through everything that is involved in a
barium enema if it isn't needed.
Can you get some more info from mom (hopefully before the test).
Marie Davis, RN, IBCLC