After you schedule a colonoscopy, your doctor will give you a list of instructions about what to eat and drink — and, perhaps more importantly, what not to eat and drink — in the days before the procedure.
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Following these directions will help ensure that your large intestine is completely empty during the colonoscopy. If it's not, the doctor may not be able to clearly see and address potential colon abnormalities, which is the whole point of getting a colonoscopy in the first place.
What Kind of Jell-O Can You Eat Before a Colonoscopy?
Although doctors' instructions may differ slightly from practice to practice, the list of foods and beverages to avoid prior to your colonoscopy will probably include red, purple, orange and sometimes blue Jell-O or other gelatin brands, along with any fluids in those hues.
But you can eat yellow and green Jell-O, which means you can enjoy flavors like lemon, lime, pineapple, green apple and even Jolly Rancher. (But always check the ingredients label for red dye just to be safe.)
And while clear Jell-O is not actually offered by the Jell-O brand, you could make your own clear gelatin and add flavoring to it yourself — you'd just still want to make sure the flavoring you were adding didn't include any red food dye in it.
Why Are Some Jell-O Colors OK to Eat But Others Aren't?
The only reason for avoiding certain colored Jell-O (along with other similarly colored foods and drinks) before a colonoscopy is that the red food dye looks like blood in the colonoscope camera view. It has nothing to do with the chemicals used to create certain food coloring.
"The hypothesis is that [red dye] can make it seem like you are bleeding, or stain the lining of the colon to make it difficult to see some of the flatter polyps," says John H. Ashcraft, DO, chief of colon and rectal surgery at the University of Kansas Health System in Kansas City.
In fact, even relatively sophisticated technology still has a hard time distinguishing red food dye from blood, according to an October 2010 article published in the journal Endoscopy.
Worst-case scenario, the red food coloring might cause your doctor to miss or misinterpret something during the colonoscopy. Best case? Well, you'd have to go through the colonoscopy process all over again.
What Else Can't I Eat or Drink Before a Colonoscopy?
The official colonoscopy prep recommendations from the U.S. Multi-Society Task Force on Cancer focus primarily on drinking lots of clear liquids the day before the procedure. Your colonoscopy doctor will provide more detailed guidelines.
In addition to avoiding red, purple, orange and sometimes blue Jell-O, you'll be told not to consume:
- Red, purple and orange flavored ices and ice pops
- Red, purple and orange hard candies like Life Savers
- Red, purple and orange sodas
- Red, purple and orange fruit juices
You'll also need to avoid eating any solid foods, including soup containing bits of dried food or seasoning. And when it comes to liquids, you'll need to stay away from alcoholic beverages and juices containing pulp or nectars. It's always best to check the ingredient panel on food packaging beforehand to verify that a given product doesn't contain any red food dye.
What Can I Eat and Drink Before a Colonoscopy?
The day before your procedure, you'll be asked to consume lots (and we do mean lots) of clear liquids. You'll want to drink more than just water and coffee or tea, because you will need some source of calories (read: energy) for the day of the colonoscopy. At the same time, you'll be losing lots of fluid (thanks to the strong laxatives you'll be taking), and you don't want to get dehydrated.
Also on the approved list of what you can eat before a colonoscopy:
- Clear soups like consommé, bouillon and broth
- Yellow or green Jell-O
- Flavored ices that aren't red, purple or orange
- Hard candies that aren't red, purple or orange
- Clear fruit juices (apple, white cranberry, white grape, lemonade)
- Clear sodas (Sprite, ginger ale, 7 Up, seltzer)
- Clear Gatorade
- Black coffee (no milk or cream)
If you have diabetes, the Memorial Sloan Kettering Cancer Center advises consuming only sugar-free liquids, ices or Jell-O.
Read more: What Can You Eat When Preparing for a Colonoscopy?
Keep in mind that these are just general guidelines; the specific instructions you receive may vary a bit. Ultimately, if you're not sure what's OK to eat as part of your clear liquid diet before your colonoscopy, check with your doctor's office. "The final word is to follow the recommendations of the doctor who gave you the [colonoscopy] instructions," Dr. Ashcraft says.
Is This an Emergency?
- The Harvard Medical School Family Health Guide: "Preparing for a Colonoscopy."
- Endoscopy: “All That is Red is Not Blood!”
- Gastroenterology: "Optimizing Adequacy of Bowel Cleansing for Colonoscopy: Recommendations From the US Multi-Society Task Force on Colorectal Cancer.”
- Memorial Sloan Kettering Cancer Center: “How to Prepare for Your Colonoscopy Using MiraLAX®.”