Anyone who’s had a colonoscopy screening for colorectal cancer will tell you that getting ready for one takes time and can be pretty inconvenient. But it’s very important to empty out your colon so the doctor can see even the tiniest trouble spot! And if everything goes well, you won’t need another colonoscopy for a long time.

1. Do it by the book. Your doctor will give you instructions—usually a list of steps to take the day before your colonoscopy. Make sure you follow them exactly, in order! If you take any medicines, your doctor will tell you when, if, and how to take them.

2. Stay in the clear. The day before the colonoscopy, you’ll be on a clear liquid diet. If you can see through a liquid when you hold the glass up to the light, then it’s okay. Sports drinks, apple juice, ginger ale—even hard candies or light-colored ice pops made of flavored water or juice—can help fight hunger while making sure the test works. Need caffeine? Black coffee and tea are okay, too.

3. Prep with power. Your doctor will prescribe a strong laxative—something that makes you “go” a lot. It isn’t the best-tasting stuff, but it goes down easier if you mix it with sports drinks or powdered drink mix and water. Avoid red-colored fluids and powders.

4. Take your time. Even though your insides may get moving soon, it’s not a race to finish the laxative mix. You’ll probably start drinking it in the evening. Follow your doctor’s directions. Sometimes you drink half and then wait a few hours for the other half. Don’t force yourself if you’re feeling full or sick to your stomach.

5. Respect your rear. Expect to visit the bathroom often, and have plenty of toilet paper! If your skin gets dry or painful, use flushable wet wipes or a soothing cream.

6. Get comfy. You may need to stay close to the bathroom, but you don’t have to be bored! Pull up a soft chair and set yourself up with a book or a magazine, or watch TV or a movie on your laptop or tablet.

7. Give yourself a prep pep talk. It takes a lot of laxative and liquid to really clean things out. You may wonder if you can really drink all that. Tell yourself: you can do this, and it’s for your health!

8. Follow color cues. By the time you are close to finishing the laxative, what comes out of you should look a lot like what’s going in. If you see dark liquid or bits of food, and you’re following the clear liquid diet, call your doctor.

9. Two hours to go—stop the flow. Don’t drink anything at all for at least two hours before your colonoscopy.

Give yourself a pat on the back. The hard part is over! You’ll be asleep while the colonoscopy is done. When you wake up, you’ll know you did the right thing to help prevent colorectal cancer!

This article was originally published on the Centers for Disease Control and Prevention website on March 27, 2018.