Prep FAQ

Frequently Asked Questions

Before contacting the on call gastroenterologist, please see if your question is answered below. It is imperative you follow the preparation instructions given to you by GSI.

Top reasons patients are canceled and have to repeat the colon preparation:

1. Not following the preparation instructions. Please read the instructions and follow them!

2. Uncontrolled blood pressure. Do not stop your blood pressure medications. Please take your blood pressure medications as you normally would with a small sip of water on the day of your procedure.

3. Eating or drinking prior to the procedure. You must have your stomach empty prior to having anesthesia in order to decrease the risk of aspiration.  You cannot drink anything for at least 4 hours prior to the procedure.

4. Eating solid food the day prior to the procedure and NOT adhering to diet recommendations.

5. Pending heart or lung studies/tests. These may include stress tests, echo-cardiograms, holster monitors, pulmonary function tests, etc. These must be completed with results prior to scheduling your procedure.

6. No responsible adult present at the time of the procedure arrival or your responsible adult leaves the facility. You must have a responsible adult with you for the procedure when you check in.

7. Your colon is not cleaned out appropriately. Please follow the instructions very closely.

8. Using oral tobacco on the morning of your procedure.

9. Recent respiratory infection or symptoms. You must be free of respiratory symptoms for 2 weeks before undergoing anesthesia.

10. Change in your health prior to the procedure. If you have a change in your health, discuss this with our nursing staff prior to the day of your procedure to confirm you are ok to proceed.

11. Being late for your appointment. You must arrive and check in 45 minutes before your scheduled procedure time.

Why do I need to do a colonoscopy preparation?
During a colonoscopy the physician visualizes the colon wall to evaluate for colon polyps which can be removed during the procedure to decrease the risk of colon cancer. If the colon is not adequately cleaned out it is difficult to visualize and the risk of missing colon polyps or other lesions is high.

Why do I need to do a low residue diet?
Starting a low residue diet 3 days prior to your colonoscopy is helpful in decreasing food items that are difficult to evacuate from the colon. Adhering to a low residue diet 3 days prior to the procedure improves your toleration of the preparation and improves your chance of a successful preparation.

Foods to Avoid

Whole-grain or whole wheat products
Brown or wild rice
Oats, Barley, and Quinoa
Raw fruit (including those with seeds, and skin such as berries)
Raw or under-cooked vegetables (including corn and winter squash)
Broccoli, cauliflower, Brussels sprouts, cabbage, kale, and Swiss chard
Dried beans, peas, and lentils
Seeds and nuts
Foods made with seeds, nuts, raw or dried fruit
Pickles, relish, and olives
Limit milk and milk products to 2 cups daily

What is a clear liquid diet?
We ask you to do a clear liquid diet on the day prior to the colonoscopy to help increase your chance of having a successful bowel preparation. If you can see through the liquid to read words on a piece of paper behind it you can have it. Examples of this would include water, chicken or beef broth, gelatin, black coffee, Gatorade or other sports drinks. Cream and milk are not clear liquids and are not acceptable. You should also not drink red or purple as this can be difficult to see through. While alcohol is a clear liquid it is not acceptable during the preparation.

Can I continue to drink liquids after I have started taking the preparation?
You are allowed to drink clear liquids all day the day prior to the procedure. If your procedure is in the morning do NOT drink anything after midnight. If your procedure is in the afternoon do NOT drink anything starting 4 hours prior to the procedure. If you drink or put anything in your mouth (except a toothbrush or blood pressure medications) your procedure will be delayed or possibly canceled (it is never a fun conversation to cancel a colonoscopy and repeat the preparation).

Can I eat solid foods?
No. You can’t eat anything solid the entire day before the procedure or the day of procedure. If you eat solid foods on the day prior to the procedure your preparation will not be clear and you may have to repeat it (once again this is never a fun conversation).

Can I smoke on the day of the procedure?
We ask that you not smoke on the day of the procedure as smoking causes significant airway reactivity and increases your risk with anesthesia.

Can I use oral tobacco on the day of the procedure?
No. If you use oral tobacco on the day of the procedure your procedure will likely be canceled or at least postponed.

Can I use edible marijuana on the morning of the procedure?
No. You can’t eat anything including marijuana products. Eating before anesthesia increases your risk of aspiration.

I lost my preparation instructions. What do I do?
Please see instructions online at: GSI Colonoscopy Prep Instructions

I was told to take a prescription preparation but the pharmacy did not receive a prescription. What do I do?
Please see the following instructions for an over the counter Miralax preparation. You can get each of these items at any pharmacy.
GSI Generic Colonoscopy Prep Instructions

Do I need to take all of the preparation?
Yes. It is definitely best to complete the entire preparation. Our goal is to have the colon completely cleared out so the physician can safely and effectively find and remove polyps. Failure to adequately prep your colon increases the risk your physician will miss something important in your colon. If your colon is not clear, you will be asked to repeat the preparation and colonoscopy again.

What can I do to tolerate the preparation better?
Some patients find it better tolerated when cool. You can cool it in the refrigerator prior to use.

What can I do to prevent issues with my hemorrhoids during the preparation?
The use of moist wipes instead of toilet paper is often helpful. A moisture barrier such as petroleum jelly or Desitin is often helpful as well.

I have done all of the colon preparation, but I have not had a bowel movement. What do I do?
Don’t panic. We would recommend to get up and walk around if possible. You can take a bottle of magnesium citrate (over the counter) to help as well. You should not take this if you have significant kidney disease or congestive heart failure.

I ate solid food the day prior to the procedure. What do I do?
Ideally you did a clear liquid diet on the day prior to the procedure, however if you did have some solid food you may still be ok. It is imperative you do the remainder of the colon preparation as instructed. If you are passing clear liquid at the end of the bowel preparation then your colon should be clear to proceed with colonoscopy.

What if I am still passing solid, brown stool at the time the procedure is scheduled?
If you are still passing solid stool up until the time of your procedure, it will likely have to be rescheduled. You may need a more extensive colon preparation for future colonoscopy preparation.

I am nauseated with the preparation, what should I do?
Cooling the preparation may help. Drinking the preparation with a straw may help as well. You should also try drinking the preparation a little more slowly.

How long will the test take?
The colonoscopy takes about 20-30 minutes. You should expect to be at the facility for 1 1/2 to 2 hours.

When should I arrive for my colonoscopy?
45 minutes before your scheduled procedure time. It is imperative you arrive on time so we can prepare you for the procedure and proceed in an efficient manner. In order to be able to
provide quality care and timely service to all patients we ask that you do your part by arriving on time.

I do not have a ride home. Can I still have my procedure?
No. You must have a responsible adult accompany you home after the procedure. It is not required they drive you home (for example, it is OK to take a cab, bus, Uber, Lift), but he/she must be with you until you arrive home safely. If you do not have someone to accompany you home, you will not be able to have your procedure. Your responsible adult must be at the facility with you
the entire time you are at the facility.

I am currently on my period. Can I still have my procedure?
Yes. It is safe to have a colonoscopy while you are having your period and it will not interfere with the exam.

Should I stop my aspirin for the procedure?
If you are on aspirin for heart disease we recommend to continue it for the procedure. If you are on it for other reasons, please hold if for 3 days prior to the procedure.


If you have other questions you feel are urgent and need to be addressed prior to business hours you can contact the on call gastroenterologist by calling the office at 918-940-8500.