Importance of a Good Colonoscopy Prep

A lot of people look to GI doctors — and rightfully so — when judging the accuracy of a colonoscopy. An experienced and well-trained gastroenterologist should be thorough when checking the colon for polyps and other irregularities. Unfortunately, even the best doctors in the world can miss polyps during a colonoscopy if a patient has not performed a good colonoscopy prep.

At the Center for GI Health, Beverly Hills gastroenterologist Dr. Nowain carefully instructs his colonoscopy patients on the proper way to prepare for the procedure. Without this cooperation from his patients, his colonoscopy exams would simply not be as effective. Read on to find out more about how to do a good colonoscopy prep.

If you would like to schedule a colonoscopy with Dr. Nowain, call (310) 657-4444.

Examples of Bad and Good Colonoscopy Preps


This is how a bad colonoscopy prep looks.


With a bad colonoscopy prep you cannot see half of the colon lumen.


This is an example of a great colonoscopy prep.


See how clearly you can see the colon lumen with a good colonoscopy prep.

How to Achieve a Good Colonoscopy Prep

As surprising as it may sound, most patients think the worst part of getting a colonoscopy is the bowel prep. As a result, our goal is to make this process as easy as possible for our patients by using a low volume preparation. Our patients are given a list of instructions that detail exactly how the colon prep should go. In this blog, we will outline the process for you.

The best way to determine on your own if your bowel prep was done correctly is if your bowel movements only contain a clear, light, or yellowish liquid. You really shouldn’t have any solid or large bowel movements.

The Day Before Your Colonoscopy

The day before your scheduled colonoscopy, you cannot have any solid food. You will be put on a clear liquid diet for 24 hours prior to your colonoscopy. With no solid food on the menu until after your colonoscopy, you may consume any of the following:

  • Water
  • Broth
  • Plain coffee (no milk allowed; sugar is okay)
  • Tea
  • Jell-O®
  • Apple, white grape, or white cranberry Juice
  • 7-up/Sprite/Ginger Ale

As part of your clear liquid diet, you cannot eat any of the following:

  • Solid food
  • Dairy products (milk, cheese, yogurt)
  • Eat or drink anything that’s purple or red
  • No red or purple Jell-O
  • No red juice (i.e. red cranberry juice)

The reason why you cannot drink anything that is red or purple is because those colors look like blood during a colonoscopy. This can make it very difficult for the physician to distinguish between food coloring and blood and would not contribute to a good colonoscopy prep.

Colonoscopy Prep: SUPREP Bowel Prep Kit

In the evening on the night before your colonoscopy appointment (approximately 7 p.m.), you should begin drinking the colon prep drink. Our patients are given SUPREP Bowel Prep Kit to clean the bowel. SUPREP is a laxative designed to cleanse the colon as a preparation for colonoscopy in adults. It is a low-volume bowel preparation that you take as a split-dose regimen.

Here is a simple four-step process for preparing and drinking the bowel prep:

  1. Pour a six-ounce container of SUPREP into a mixing container.
  2. Add cool drinking water to the 16-ounce line on the mixing container.
  3. Drink all the liquid in the container.
  4. Drink two more 16-ounce glasses of water over the next hour.

It is very important that you drink the all the liquid between 7 and 8 pm.

A lot of people do not like the way the prep tastes. As a result, some people add lemonade or other clear tasty liquids to make the drink taste better. The downside to this is that now there is more liquid to drink, and sometimes it still isn’t enough to make the prep taste better.

After you drink the bowel prep, you are allowed to continue drinking clear liquids until midnight. However, you cannot have anything to drink after that.

Almost all of our patients tolerate this preparation very well. However, if patients cannot handle the SUPREP, we can make other arrangements. These include pills, laxatives, suppositories, or enemas. The end goal is to have a good colonoscopy prep one way or another.

On the Day of Your Colonoscopy

During your initial office visit, you will be instructed on when to take the second bottle of SUPREP based on the time that your colonoscopy is scheduled. Afterward, you may continue drinking clear liquids; however, do NOT eat or drink ANYTHING for 6 hours prior to your colonoscopy. You will be under anesthesia and sleeping during the colonoscopy, so food in your stomach can be very dangerous during the procedure if you throw up (which is rare). We want to make sure that your stomach is empty.

If you need to take a pill, just take it with a small sip of water. Your doctor will instruct you as to the timing of your other medications, and as always feel free to contact him if you are not sure.

Bad Prep Colonoscopy Preps

A bad colonoscopy prep will result in the following:

  • Missed polyps or cancers
  • Longer procedure times
  • More anesthetics needed because of the longer procedure time
  • Need for more frequent interval colonoscopies due to possibility of something being missed.

You don’t want your colonoscopy to be a waste of time, especially not after you’ve spent the previous day eating nothing but clear liquids. Not to mention the fact that it is vital your doctor spots a polyp if it’s there during your examination. Finding colon cancer in its early stages is the key to treating the disease. If you perform a good colonoscopy prep, your doctor will have a great chance to find any polyps that could eventually grow into colon cancer.

If you would like to schedule a consultation with one of the finest gastroenterologists in Beverly Hills, contact Dr. Ari Nowain today by calling (310) 657-4444 or fill out the online contact form on this website.