How long should a patient with pyloric obstruction fast before undergoing gastroscopy?

Patients with pyloric obstruction generally need to fast for 6–8 hours before undergoing a gastroscopy.

When pyloric obstruction is suspected, a gastroscopy is required to assess the severity of the obstruction. However, the stomach must be completely emptied before the procedure can be performed. Because pyloric obstruction slows gastric emptying, fasting for 6–8 hours is necessary to ensure that food in the stomach has been adequately cleared, which facilitates accurate examination. If the stomach is not sufficiently empty, residual food may impair camera visibility and could lead to discomfort such as nausea or vomiting due to irritation from the endoscope. Therefore, fasting for 6–8 hours prior to gastroscopy in patients with pyloric obstruction helps prevent missed or incorrect diagnoses.

Gastroscopy is an invasive procedure. Patients should promptly communicate with their doctor if they experience any discomfort during the examination. It is important to stay relaxed and avoid excessive anxiety. When necessary, the procedure may be performed under general anesthesia.