Linzess® (linaclotide) is a prescription medication used to treat irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC) in adults. It works by increasing fluid secretion in the intestines and accelerating movement through the digestive tract, which helps relieve constipation and abdominal pain. Linzess® is taken once daily on an empty stomach, usually at least 30 minutes before the first meal. It is not a laxative but a guanylate cyclase-C (GC-C) agonist that targets the underlying cause of symptoms in IBS-C and CIC.