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Colonoscopy Prep FAQs
in Denver

What if I ate some food on the day before my colonoscopy?

If your colonoscopy appointment is after 1 p.m. the next day, you are allowed to have a light breakfast before 9 a.m. the day prior (see the prep instructions on the SDG website). Otherwise, solid food the day before the procedure can cause the colonoscopy prep to be less effective, and we may not be able to see well enough to consider it an adequate exam. Most of the time, if you add 2-3 capful doses of Miralax or a bottle of magnesium citrate mid-day, and begin the prep that evening as instructed, this will be enough to still achieve a good prep for the exam. The goal is to have urine or tea-colored movements by the end of your prep, and often this can still be achieved.

I have eaten some seeds and nuts. Is it ok to proceed with the colonoscopy?

Yes. If seeds and/or nuts remain in the colon at the time of the colonoscopy, they can cause issues with visualization and can clog the suction channel on the camera. Typically, these are cleared out well enough with the prep to not cause any problems. However, adding a couple of glasses of water in addition to the standard instructions, especially with the second half of the prep the morning of the procedure, can help clear these from the large intestine and allow for an adequate exam as scheduled.

What about aspirin and NSAIDs, iron supplements and fish oil ingestion?

A colonoscopy can be safely performed without interruption of aspirin, NSAIDs, iron supplements or fish oil. For patients with a history of cardiac stents or stroke, aspirin should not be held for this procedure.

Im unsure how to take my prep, or I don't have prep instructions. I need clarification?

Go to and use the drop-down menu under “Patient Resources” to select Colonoscopy Prep. Find your prep on the list and follow the written instructions. Read carefully one week before your procedure.

My prep box and your instructions are different, what do I do?

Please discard the instructions that come with the prep kit and refer to our website for detailed instructions for your colonoscopy prep.

What if I take a weight loss medication such as phentermine?

You need to hold this at least 7 days before the colonoscopy. You can continue to take other weight loss medications.

What if I don't have my colonoscopy preparation instructions?

Go to and use the drop-down menu under “Patient Resources” to select Colonoscopy Prep. Find your prep on the list and follow the written instructions. Read carefully one week before your procedure. Preps start with diet changes the day before your colonoscopy.

What if I vomit my colonoscopy preparation after ingestion?

Vomiting is unfortunately common with the prep, and despite it, the bowel is typically cleaned enough for an adequate exam. Often, nausea will subside if you slow down your intake of the prep solution and/or the water, by using a straw and chilling the liquid. Take a break and wait 15-30 minutes, then try again at a slower rate. For the second prep dose, at least double the time to ingest the prep.

What if there is a delay in bowel movements after the first dose of the prep?

The prep will begin working eventually. It can sometimes take a couple of hours to start having an effect, and in patients with constipation, it can take longer. Adding a couple of glasses of water to your prep, in addition to the standard instructions, and taking Dulcolax/bisacodyl tablets at the beginning of the prep will help things start more quickly. Only contact the on-call physician after the second dose of the prep if you still do not think it is working well enough.

What if I did not have a good prep before my last colonoscopy?

Contact your gastroenterologist at least two weeks before your procedure to discuss the right prep plan for you.

I ate/ drank something red or purple. What do I do now?

That's OK! Continue with the prep according to the instructions, avoid red and purple liquids from here on, and the prep should do fine to wash everything out.

Do I take my medications on the day of the procedure?

You can take your scheduled medications other than blood thinners on the day of the colonoscopy. It is important that you take heart and hypertension medications according to your normal schedule, and before the procedure is fine (DO NOT MISS DOSES!). If you have an inhaler, please use it before you come in for the colonoscopy and bring it with you. If you are diabetic, contact the prescriber of your diabetes medications to discuss any changes needed for your medication regimen around the procedure.

I need to cancel my procedure for tomorrow, how do I do this?

If it is after hours, call the answering service at 303-788-8888 and let them know. They will alert the office first thing in the morning. Otherwise, call at 7:30 a.m. when the office opens and our staff will help quickly guide you through the cancellation process.

Can I have a colonoscopy if I am menstruating?

Yes, you can still have your procedure and wear a tampon if you prefer.