Colonoscopy Prep 101: 4 Steps for Success According to Doctors

A colonoscopy is a routine screening that allows doctors to examine the inside of your colon for polyps or inflammation – signs of possible colorectal cancer. It’s one of the most effective tools for detecting problems early, often before symptoms even appear. While the procedure itself is typically quick and low-risk, the preparation beforehand is what many people find most challenging. 

Colonoscopy prep is designed to fully clear your colon so your doctor can get the most accurate view of your large intestine. This process usually involves dietary changes, clear liquids, and a prescribed laxative in the days leading up to your appointment. Following each step carefully is essential to avoid repeat procedures, ensure accurate results, and ensure that the procedure goes smoothly. With the right preparation, you can approach your colonoscopy feeling informed, confident, and ready.

1. Adjust Your Diet (3–4 Days Before)

A few days before your procedure, you’ll switch to a low-fiber (low-residue) diet to make bowel prep easier.

What to eat:

• White bread, pasta, rice
• Cooked vegetables (no skin)
• Skinless fruits
• Lean meats like chicken or fish
• Eggs

What to avoid:

• Seeds, nuts, popcorn
• Whole grains
• Raw vegetables
• Fruit with skins or seeds
• Tough meats

Your doctor may also ask you to pause certain medications or supplements. Always confirm before stopping anything prescribed.

2. Switch to Clear Liquids (1–2 Days Before)

You’ll stop eating solid foods and move to a clear liquid diet one to two days before your procedure.

What you can have:

• Water
• Clear broths
• Plain coffee or tea (no milk or cream)
• Sports drinks (not red or purple)
• Apple or white grape juice (no pulp)
• Gelatin (avoid red or purple)

Avoid any liquids with red or purple coloring, as they can interfere with the procedure.

3. Complete Your Bowel Prep (Day Before)

This is the most important step. You’ll take a prescribed laxative to fully empty your bowels.

• Prep may come as a liquid, powder, or tablets
• Most people drink the solution over several hours
• Stay near a bathroom and plan to be home
• Finish the full dose as instructed

Tip: The taste can be unpleasant, but chilling the liquid, using a straw, or following with an approved clear drink can help.

4. Finish Prep + Get Ready (Day Of)

• Finish your final dose of prep solution 4–5 hours before your appointment
• You can drink clear liquids until about 2 hours before the procedure
• Avoid alcohol or substances that affect awareness
• You’ll change into a gown and receive sedation (not usually full anesthesia)

If you’re still having frequent nausea or bowel movements, plan ahead for comfort when traveling to your appointment.

Your doctor will recommend the best option for you. Common forms include:

Drink mixes (most common):

• GoLYTELY, MiraLAX, MoviPrep, TriLYTE
• Often better for those with certain health conditions

Tablets:

• SUTAB, Suprep, OsmoPrep
• May be easier to take but not ideal for everyone

Always follow your provider’s specific instructions.

How to Make Prep Medications Easier to Take

• Drink the solution quickly to minimize the taste
• Use a straw to help it go down faster
• Ask your doctor if flavoring is allowed
• Suck on lemon or hard candy afterward to reduce aftertaste

• Wear loose, comfortable clothing
• Use soft or medicated wipes instead of dry toilet paper
• Apply barrier cream to prevent irritation
• Keep entertainment nearby (books, shows, phone)