Colonoscopy Diet Protocols

Clear Liquid Diet

At Hamilton Endoscopy & Surgery Center, we advise that a very important component of any preparation for colonoscopy (or certain other procedures) is a modified diet consisting of only clear liquids for one or two days prior to the procedure. This is because the stomach, and both the small, and large intestine may need to be empty to provide the surgeon with a clear view of the area. The liquids-only colonoscopy prep protocol may also be recommended as a short-term diet if you have certain digestive problems, such as nausea, vomiting, or diarrhea. You may also have to continue a liquid diet for a period of time after your colonoscopy or certain other types of procedures.​

While no solid food is allowed during your colonoscopy prep, certain liquids are allowed so that you can maintain adequate hydration and provide important electrolytes, such as sodium, potassium, and energy at a time when your normal diet isn’t possible or recommended.

What to Eat Before a Colonoscopy

The following foods are generally allowed in a clear liquid diet as a preparation for colonoscopy:

  • Water (plain, carbonated, or flavored)
  • Fruit juices without pulp, such as apple or white grape juice
  • Fruit-flavored beverages, such as fruit punch or lemonade
  • Clear carbonated drinks
  • Gelatin
  • Tea or coffee without milk or cream
  • Clear, fat-free broth (bouillon or consomme)

Depending on your medical condition, your physician may customize this list. For certain tests, such as a colonoscopy or other colon exams, we may ask you to avoid liquids or gelatin with red coloring. Any foods not on the above list should be avoided in your preparation for colonoscopy.

Always Follow the Diet as Prescribed

Due to the lack of adequate calories and nutrients, a clear liquid diet should only be followed as part of a colonoscopy prep for only a few days or as directed by your doctor.

As related to preparation for a medical procedure, only follow the colonoscopy prep or diet instructions exactly as prescribed. Failure to follow the diet as prescribed can run the risk of an inaccurate test and you may have to reschedule the procedure for another time.

An Important Message for Diabetics

Diabetics need to be especially mindful of their colonoscopy prep. If you have diabetes, speak with your physician as to special precautions that may need to be taken as related to managing your blood sugar levels on a clear liquid diet. Blood sugar levels should be monitored and the transition to solid foods should be done as quickly as possible.

Example Colonoscopy Prep Diet

A typical clear liquid diet menu that your doctor will advise prior to your colonoscopy or other procedure may look like the following:


  • 1 glass pulp-free fruit juice, color less 
  • 1 bowl gelatin, color less 
  • 1 cup of coffee or tea, without dairy products
  • Sugar or honey, if desired


  • 1 glass pulp-free fruit juice, clear
  • 1 glass water
  • 1 cup broth
  • 1 bowl gelatin


  • 1 cup pulp-free clear juice or water
  • 1 cup broth
  • 1 bowl gelatin (plain, no color)
  • 1 cup coffee or tea, without dairy products
  • Sugar or honey, if desired


  • 1 glass fruit juice (pulp-free)
  • 1 bowl plain gelatin (no color)
  • 1 pulp-free ice pop
  • 1 cup coffee or tea, without dairy products, or a soft drink
  • Sugar or honey if desired
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