Mesalamine should be safe during breastfeeding, for reasons already
mentioned by Jack.  One caveat:  it is a derivative of sulfasalazine
(without the sulfa).  There have been rare cases of this med *causing* a
drug-induced colitis, including in a breastfed baby whose mother was
taking the med.  This is reversible when the medicine is stopped, so not
a reason not to try taking the med.

Formula fed babies have higher rates of colitis, which is increased in
family members, so this mom should receive all possible support to
continue breastfeeding (for this as well as the usual reasons!)

--
Anne Montgomery, M.D.
[log in to unmask]
St.Peter Hospital Family Practice Residency
Olympia, WA