An upper endoscopy (EGD) is a common procedure used to visually examine the lining of the upper digestive tract, including the esophagus, stomach, and the first part of the small intestine. A successful examination requires the stomach to be completely empty so the physician can clearly see the internal tissues without obstruction. Specific dietary restrictions are mandated the day before the procedure to achieve this. Failure to properly prepare can leave residue that obscures the view, potentially leading to a missed diagnosis or the need to reschedule the examination.
Transitioning Away From Solid Foods
The day before an EGD marks the transition from a regular diet to a liquid-only regimen designed to ensure minimal digestive residue remains in the stomach. While some protocols allow a light, low-fiber breakfast, the general instruction is to halt the consumption of all solid food entirely. This restriction often begins around noon, initiating the clear liquid phase for the remainder of the day.
Certain foods must be stopped because they contain components that linger in the digestive tract. High-fiber items, such as nuts, seeds, whole grains, and raw vegetables, are particularly slow to digest. Even small particles from these foods can interfere with the visualization of the stomach lining, so they are strictly prohibited.
The restriction also includes specific colors, namely red, purple, and sometimes blue or orange dyes. These pigments can adhere to the mucosal lining, creating an appearance that might be mistakenly interpreted as blood during the procedure. Dairy products, such as milk or cream, must also be avoided because their opaque nature and fat content contribute to gastric residue and cloudiness.
Defining and Utilizing Clear Liquids
Once the clear liquid diet begins, the focus shifts to maintaining hydration and electrolyte balance using only transparent fluids that leave no particulate matter behind. A liquid qualifies as “clear” if you can easily see through it when poured into a glass. This ensures that anything consumed is quickly and completely absorbed by the body.
Many common beverages and foods are permissible within this transparent framework, providing necessary calories and electrolytes without leaving residue.
- Plain water
- Clear broth (chicken, beef, or vegetable)
- Pulp-free juices (white grape or apple)
- Clear carbonated sodas
- Sports drinks that are not red or purple
- Plain gelatin
Black coffee or plain tea are permitted, but they must be consumed without any form of milk, cream, or non-dairy creamer, as these additions violate the clear-liquid rule. Liquids that are opaque or contain pulp, such as orange juice, tomato juice, or smoothies, must be avoided completely. Alcohol is also prohibited during the preparation period.
Critical Timing and Medication Guidance
Adherence to the final timing instructions is important for patient safety, particularly concerning the necessary fasting period before the endoscopy. The most restrictive phase is known as nil per os (NPO), meaning nothing by mouth, which typically begins six to eight hours before the scheduled procedure time. This prohibition includes all liquids, even small sips of water.
The NPO status is a measure to prevent pulmonary aspiration, a serious complication where stomach contents are inhaled into the lungs during sedation. When a patient is sedated, protective airway reflexes are temporarily impaired, and an empty stomach significantly reduces this risk. Failure to observe the NPO window will frequently result in the cancellation of the procedure.
Medication Adjustments
Patients must consult with their prescribing physician regarding morning medications, especially those for diabetes and blood clotting.
Diabetes and Insulin
Diabetic medications, including insulin, are often withheld or significantly adjusted on the morning of the procedure to prevent hypoglycemia due to fasting.
Blood Thinners
Blood-thinning agents may need to be temporarily stopped days in advance to minimize the risk of bleeding if a biopsy is performed.