Clear Liquids

Purpose
A diet of clear liquids maintains vital body fluids, salts, and minerals; and also gives some energy for patients when normal food intake must be interrupted. Clear liquids are easily absorbed by the body. They reduce stimulation of the digestive system, and leave no residue in the intestinal tract. This is why a clear liquid diet is often prescribed in preparation for surgery, and is generally the first diet given by mouth after surgery. Clear liquids are given when a person has been without food by mouth (NPO) for a long time. This diet is also used in preparation for medical tests such as sigmoidoscopy, colonoscopy, or certain x-rays.

Nutrition Facts
A clear liquid diet is not adequate in calories and nutrients. It should not be used for more than five days unless high-protein gelatin or other low-residue supplements are added.

What is a clear liquid?
A good rule-of-thumb is anything you can see through. For example, apple juice is a clear liquid; milk is not.

Preparing for a medical test
It is important that the clear liquid diet be followed exactly. Remember that the value of the examination will depend on getting a thoroughly clean digestive tract.