More recently, the role of a non-osmotic release of antidiuretic hormone (ADH), low dietary solute intake, and excessive and rapid free fluid intake have also been considered as contributing factors for hyponatremia associated with colonoscopy.1 Non-osmotic release of ADH is usually associated with vomiting, pain, anxiety, stress, and hypoglycemia.6 Our patient had an excessive intake of free water the day before a colonoscopy. The gene discussed is AVP; the disease is Anxiety.