Linzess (linaclotide) is a guanylate cyclase-C (GC-C) agonist used to treat adults with irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC). It works by increasing the secretion of chloride and bicarbonate into the intestinal lumen, which helps increase intestinal fluid and accelerate bowel movements, relieving constipation and associated symptoms such as abdominal pain and bloating. Linzess is taken orally once daily on an empty stomach, usually 30 minutes before the first meal of the day. Common side effects include diarrhea, abdominal pain, gas, and bloating. Patients should follow their healthcare provider’s instructions regarding dosage and use.