Drinking water is generally not recommended for 4 hours prior to a gastroscopy, there is no restriction on drinking water prior to a general colonoscopy, and water is prohibited 4 hours prior to the exam for a painless colonoscopy.
Bowel preparation for gastroenteroscopy is different. Before performing a gastroscopy, you need to make sure that the stomach is as free as possible from food debris and excess fluid, and if there is no obstruction of the outflow tract, you are prohibited from drinking water 4 hours before the gastroscopy.
Before the general colonoscopy, it is necessary to make sure that there is no food residue and feces in the intestines as much as possible, and it is generally recommended that the patient take laxatives to clean the intestines one night in advance, and the process of taking laxatives itself requires about 3 liters of water until the discharge of watery stools can be done, so there is no limitation of drinking water for this examination.
Painless colonoscopy, on the other hand, requires general anesthesia, and drinking water is prohibited 4 hours before the examination.
It is recommended that patients preparing for gastroenteroscopy should follow the doctor’s instructions for good intestinal preparation.