To Willow Ward---

Is your question what makes gas or what makes gas pains?

Gas is usually the by product of the breakdown of any undigested food by
bacteria that reside in the colon (even babys have colonic bacteria).  Even
though mother's milk is competely digestable it is not completey digested.
(It goes through the intestine fairly quickly so that not all of it comes in
contact with the intestinal lining. This portion passes into the colon where
it is fed on by the colonic bacteria. It is certainly possible that certain
food products that pass through the blood stream into the mother's milk
result in greater gas production by colonic bacteria than other products.

Gas pains are another story.  In fact "gas pain" may have nothing at all to
do with gas.  Pain that all humans (including babies) feel as gas pain is
actually increased pressure in the intestine.  This can occur because of
distension of the intestine (excess gas production) or because of increased
strength of contractions.  I suspect that various food products passed into
the milk as food antigens result in increased strength of the baby's
peristaltic contractions which in turn is sensed as increased intestinal
pressure (="gas pains). Broccoli etc probably contain such soluble food
antigens which can pass (through the mother's intestine) and into her milk
supply causing increased intestinal contractions in the child.

I hope this answers your question,

Peter Salomon, MD
Gastroenterologist (father of two breast fed babies and husband of one LLLL,
IBCLC-in-training)