Some inspection items have strict requirements on drinking water, and drinking water before physical examination is not recommended. For example, barium meal examination of upper digestive tract, drinking water before examination can not let barium sulfate stay in the stomach, which will affect the examination results, so drinking water is strictly prohibited.
Drinking water before B-ultrasound examination of liver and gallbladder will stimulate gallbladder contraction, lead to bile excretion and affect the results of B-ultrasound examination. The swallowing action when drinking water will be fed back to the hunger center of the brain, which can mobilize the preparation for absorbing and digesting food, leading to the decomposition of liver glycogen and the release of glucose, which will lead to an increase in blood sugar. Therefore, drinking water before blood sugar test is not recommended.