AQP9 and constipation disorder: Some studies have suggested that rats with constipation may have a greater absorption of water in their colons and less secretion of intestinal fluid because of active expression of AQP3 and AQP9 concluded that a significant increase in AQP3 and AQP9 in rats’ colon resulted in intestinal smooth muscle spasms, and a significant increase in water absorption, affecting the frequency of intestinal peristalsis, and leading to constipation (13, 14).