GUCY2C and chronic diarrheal disease: Mutations in guanylate cyclase 2C (GUCY2C), an intestinal receptor for bacterial heat‐stable enterotoxins cause relatively mild early‐onset chronic diarrhea and is associated with increased susceptibility to IBD, small‐bowel obstruction, and esophagitis.44 Although the exact molecular mechanism behind the familial diarrhea is yet to be determined, it has been shown that the expression of mutant GUCY2C results in increased production of cGMP, possibly underlying the hyperactivation of CFTR, leading to increased chloride and water secretion from enterocytes.