Purpose

A clear liquid diet is often used before tests or procedures that require an empty stomach or clear intestines. For example, you may need to have a clear liquid diet before a colon exam, also called a colonoscopy. Or you may need to be on a clear liquid diet before and after certain types of surgery. A clear liquid diet may be recommended for a short time if you have certain digestive problems, such as nausea, vomiting or diarrhea.