Linzess is felt to act as a guanylate cyclase-C agonist. An agonist increases the activity of a process, the opposite of an antagonist. Linzess seems to act locally on the surface of the inside of the intestinal lining cells and by activation of guanylate cyclase-C increases levels of intracellular cGMP (cyclic guanosine monophosphate) which results in increased levels of chloride and bicarbonate in the intestinal lumen and speeds up gastrointestinal transit.

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