Linaclotide is a small peptide agonist of guanylate cyclase-C (GC-C) receptors located on the luminal surface of intestinal epithelial cells. Activation of these receptors stimulates the secretion of chloride and bicarbonate into the intestinal lumen. This increase in electrolytes draws water into the intestine, which increases intestinal fluid, accelerates transit, and facilitates the passage of stools.

Linaclotide is used in adults to treat irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC). It is also used in children aged 6 to 17 years to treat functional constipation. It is administered as a once-daily oral capsule taken on an empty stomach. The capsules must be swallowed whole, or their contents can be sprinkled over applesauce or mixed with water for patients who have difficulty swallowing. While linaclotide controls the symptoms of these conditions, it does not cure them. Its unique mechanism of action makes it a targeted therapy for constipation-predominant functional gastrointestinal disorders.