A 14-amino acid synthetic peptide related to the endogenous guanylin peptide family.Administered in moderate-severe constipation from irritable bowel syndrome and in idiopathic chronic constipation. It acts locally in the intestine, without being absorbed (EMA 2016). It is metabolized in the intestine obtaining its main active metabolite, des-tyrosine. Both linaclotide and des-tyrosine are digested by intestinal enzymes and transformed into natural amino acids. Since the last update we have not found any published data on its excretion in breast milk. Its pharmacokinetic data (zero or negligible intestinal absorption with undetectable plasma levels and high molecular weight) make it very unlikely that significant amounts will pass to breast milk (EMA 2016).