Colonoscopy Prep: Frequently Asked Questions

Where can I find my prep instructions?

You should have received your instructions via MyChart in a patient message. If you cannot locate them there or do not have access, please visit our main gastroenterology page and look for the instructions for your prescribed prep at the bottom of the page.

I just started drinking the prep — how long until it starts working?

Most people start having bowel movements within 6–8 hours after starting the prep. Everyone’s a little different, so don’t worry if it takes a bit longer. Keep drinking as instructed until you have a bowel movement.

My stomach feels bloated, or I feel nauseated. What should I do?

• Take a 15–30-minute break from drinking.
• Walk around to help your stomach settle.
• Sip the prep more slowly.
• Chill the prep or drink it through a straw.
• Use hard candy or a lemon

If you vomit and can’t keep the prep down, please call the office during normal business hours to reschedule your procedure to a later date.

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I’ve had several bowel movements, but my stool isn’t clear yet. Should I keep going?

Yes — finish the entire prep as directed. Your stool should look like clear or yellow liquid (like lemonade or light tea) when your colon is clean enough.

My last dose is early in the morning — do I really have to wake up to finish it?

Yes. The second dose (“split prep”) is very important. Taking it too early or skipping it can leave stool in your colon, which may cause your doctor to reschedule your procedure.

I’m running to the bathroom a lot. Is that normal?

Yes! That means it’s working. To make it more comfortable:

• Stay near the bathroom.
• Use soft toilet paper or unscented wipes.
• Apply a barrier cream (like Vaseline, Aquaphor, or Desitin) to prevent irritation.

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Can I drink water or clear liquids between doses?

Absolutely — staying hydrated helps the prep work better and keeps you comfortable. Drink clear liquids (water, broth, tea, Gatorade, apple juice, popsicles, etc.) until 4 hours before your procedure time.

I accidentally ate something solid. What should I do?

Call your office during normal business hours and let them know what and when you ate.

I’ve finished all the prep, but my stool is still brown or cloudy.

Sometimes it takes longer for the prep to clear everything out. Keep drinking clear liquids and stay near a restroom. If it still hasn’t cleared up a few hours before your arrival time, please contact the endoscopy center (FBEC – 6:30 a.m.–3:30 p.m. and MWH or Stafford Hospital 6:30 a.m.–3:30 p.m.) for advice.

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Can I take my regular medications tonight or tomorrow morning?

You can usually take most regular medications with a small sip of water, unless told otherwise. If you’re on blood thinners, diabetes medication, or iron supplements, follow the instructions given by your provider or call the office if unsure.

I’m worried I won’t make it to the bathroom in time.

• Stay close to the bathroom.
• Wear comfortable clothes.
• Use bathroom-safe mats or towels if needed.

This stage passes once your bowels are clear — hang in there!

How will I know when I’m “done”?

You’re done when your bowel movements are mostly clear or pale-yellow liquid with no solid pieces. That means your colon is ready and you can rest before your procedure.

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I finished the prep early. Can I go to bed?

Yes! Once your stool is clear, you can rest. Just remember not to eat or drink anything (including water) within 4 hours of your procedure unless instructed otherwise.

Who do I call if I have problems tonight?

If you have:

• Severe vomiting
• Dizziness that won’t go away

Call your GI office or the on-call provider. If you have severe abdominal pain, fever, or bleeding, go to the emergency room right away.

What if I need to cancel or reschedule my procedure?

Please contact the scheduling team during normal business hours so they can assist you.

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