Mesalazine is badly absorbed by the intestine, serum levels are low with scant excretion into breast milk. N-acetyl-5-ASA is an inactive metabolite which is excreted into breast milk but not higher than 10% of relative infant's dose. No harm effects among breastfed infants from treated mothers have been reported, except for rare cases of diarrhea reported in the 80's with the use of Mesalazine compounds different to Balsalazide. In a review of 121 cases and 121 controls, the authors failed to observe those findings. (Moretti, 1989). Expert consensus supports the compatibility of Mesalazine during breastfeeding.