A clear liquid diet is prescribed for short periods for specific medical purposes. It helps your gastrointestinal tract heal from severe bouts of disease, such as diverticulitis, and it helps clear it out before certain tests and procedures, such as colonoscopy.
A clear liquid diet is medically prescribed for short periods to rest and clean out your digestive tract while providing adequate short-term hydration and some energy. Just like it sounds, the diet consists of clear liquids and foods that melt into clear liquids (like Jell-o®). It excludes solid foods and liquids that you can’t see through (like milk). Clear liquids are easily absorbed by your digestive system, and they also allow technicians to see clearly into your digestive tract during an imaging test, such as a colonoscopy.
The diet is usually prescribed for one of three reasons:
This is not a prescribed weight-loss diet. It’s not particularly nutritious and includes a lot of empty calories from refined sugar. The diet is designed to require minimal effort on the part of your digestive system while providing hydration, some minerals and electrolytes, and a little energy to get you through. The clear liquids also help clear out built-up residue in the digestive tract that can worsen gastrointestinal symptoms and clutter up imaging tests.
The clear liquid diet includes:
Your healthcare provider will give you more specific directions on the amounts of each type of liquid you should consume. If the diet is prescribed before an imaging test, you might be asked to exclude the color red. Red liquid can resemble blood on an imaging test.
The diet is usually only prescribed for a few days. If it is prescribed for longer, it will be modified with certain supplements to provide more adequate nutrition over the longer term.
The health benefits are primarily from giving your digestive system a chance to rest and heal from severe symptoms. If you have inflammation from pancreatitis, gastritis or inflammatory bowel disease, the clear liquid diet can give it a chance to calm down. If you have diverticulitis, an infection in your colon, the inflammation is aggravated by poop in the colon. A clear liquid diet for a few days can help clear that out.
If you have severe diarrhea or vomiting, the clear liquids can restore your depleted water, energy and electrolytes without triggering further diarrhea or vomiting. However, the clear liquid diet is not nutritionally adequate for more than a few days. In most cases, your healthcare provider will want you to progress as soon as possible to a full liquid diet or “soft” (low fiber) diet to prevent malnutrition.
Contact your healthcare provider if you experience:
A full liquid diet includes all liquids and foods that become liquid at body temperature. Shakes, milk, frozen yogurt and creamy soups are allowed, as long as they don’t have any chunks or food particles in them. A full liquid diet is prescribed for similar reasons as the clear liquid diet — to rest the digestive system after illness or surgery and reintroduce it slowly to normal eating — but it’s a less severe diet for less severe cases. Some people need to start on the clear liquid diet first before progressing to the full liquid diet. Those who are preparing for an imaging test will need to stick to clear liquids to keep their digestive tract clear.
A note from Cleveland Clinic
A clear liquid diet is a brief but important intervention. It’s a safety measure that keeps you hydrated before and/or after surgery. It can help your gastrointestinal system heal and help healthcare providers get a better look inside at what’s troubling you. It might seem difficult, but most people manage it well for a day or two. While on the clear liquid diet, follow your healthcare provider’s guidance carefully. Your digestive system will thank you, and may even reward you with rapid relief.
Last reviewed by a Cleveland Clinic medical professional on 09/17/2021.
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