LINZESS (Linaclotide) is a medication prescribed to either irritable bowel syndrome with constipation (IBS-C) or chronic idiopathic constipation (CIC). Patients with IBS-C and CIC have chronic symptoms of constipation and reduced passage of stool. LINZESS works by attaching to guanylate cyclase-C (GC-C) on the surface of intestinal epithelium cells. The activation of GC-C receptors increases the compound cyclic guanosine monophosphate, which causes intestinal cells to excrete chloride and bicarbonate and pull fluid into the intestinal space. LINZESS may also help to stop muscle contractions of the abdomen that cause pain. How long does it take LINZESS to work? Most patients have maximum relief of constipation by the second week of treatment.