The transmembrane receptor guanylyl cyclase‐C (GC‐C), expressed on enterocytes along the intestine, is the molecular target of the GC‐C agonist peptide linaclotide, an FDA‐approved drug for treatment of adult patients with Irritable Bowel Syndrome with Constipation and Chronic Idiopathic Constipation. The gene discussed is GUCY2C; the disease is irritable bowel syndrome.