Cannabis Science

Can You Smoke Weed Before a Colonoscopy?

man smoking weed before colonoscopy

If you have a colonoscopy coming up, you’re probably nervous about the procedure. You’ll probably want to reach for some marijuana to calm your nerves. But can you smoke weed before a colonoscopy? Here’s what we know. 

Photo: Unsplash

What is a Colonoscopy? 

A colonoscopy is an examination of your colon and rectum. 

According to the Mayo Clinic, colonoscopies look for changes such as cancer, swollen, irritated tissue, or polyps. Colonoscopies are also a treatment. 

The Mayo Clinic says, “Sometimes, a colonoscopy may be done for treatment purposes, such as placing a stent or removing an object in your colon.”

Doctors can look for abnormalities in your colon and rectum by putting a long tube with a camera at the end. 

Even though that may sound a little scary, the Mayo Clinic reassures that a colonoscopy has few risks, and the procedure lasts 30-60 minutes. 

Of course, you will likely feel some discomfort. However, the Mayo Clinic says you may get sedation or a combination of sedation and pain medication to increase your comfort levels. 

Can I Smoke Weed Before a Colonoscopy?

No, you can’t smoke weed before a colonoscopy. 

The amount of hours between your marijuana consumption and colonoscopy may vary from clinic to clinic.

Therefore, it’s probably best to ask your doctor how long you need to quit weed before your procedure. 

US Digestive Health says, “Please cease all medicinal and recreational smoked or vaporized cannabis (weed) 12 hours prior to surgery.”

If you’re considering reaching for an edible or gummy, don’t. 

US Digestive Health says that you’ll have to stop taking edible cannabis 8 hours before surgery. 

On the other hand, Boulder Medical Center says that you should stop consuming marijuana, in all of its forms, 24 hours before the procedure. 

While neither of these sources mentioned why you should avoid marijuana before the colonoscopy, it is likely due to its interference with sedation. 

It’s the same reason why you’re told to avoid weed before you have surgery. 

According to the American Society of Anesthesiologists, avoid marijuana before sedation and surgery because of the:

  • Level of anesthesia you’ll need
  • Medication you may need after the procedure
  • Risk of nausea and vomiting 
  • Possibility of withdrawal symptoms 

You should also let your doctors know if you regularly consume weed in any way because you may need more anesthesia.

Harvard Health says people who consume marijuana regularly “generally need larger doses of anesthesia medicines in order to achieve the same degree of sedation. If you don’t tell your anesthesiologist how much marijuana you smoke, he or she may underestimate how much anesthesia will be needed for you to “go to sleep” and stay asleep during your procedure.”

The good news is there are several options available for your colonoscopy. 

The American Society of Anesthesiologists says your sedation options are:

  • None
  • Minimal/Light
  • Moderate
  • Deep
  • General Anesthesia

If you plan on using anesthesia, put down your bong or blunt before your procedure.

Can I Vape Before a Colonoscopy? 

Vaping is not allowed before your colonoscopy, either. 

Just like with smoking weed, the time you should stop using your vape will vary between clinics.

CaroMont Health says you should stop using your vape 6 hours before your appointment. 

“Six hours before your appointment, stop using cigarettes, chewing tobacco, snuff, or vapes.”

The reason you should avoid tobacco-containing products before your procedure is because it may interfere with your sedation. 

Gastroenterology Consultants of San Antonio says, “Along with increasing stomach contents, chewing tobacco also raises nicotine levels in the blood which may affect anesthesia recovery and increase the risk of complications. It’s best to quit all nicotine-containing products at least 24 hours prior to your appointment.”

Can I Take CBD Before a Colonoscopy? 

No, you can’t take CBD before a colonoscopy. 

CBD oil, according to US Digestive Health, must be stopped 8 hours before your procedure. 

Unfortunately, we haven’t found many sources that speak about using CBD before a colonoscopy; therefore, ask your doctor about it to be sure.  

Can I Drink Alcohol Before a Colonoscopy?

No, avoid alcohol for up to 24 hours before your procedure.

The New York Times says, “And whatever you do, don’t drink alcohol the day before your procedure. While it technically might be a clear liquid, alcohol can cause dehydration and interfere with sedation, which can make for a dangerous combination.”

CarMont Health also says to avoid alcohol because of the risk of dehydration and renal (kidney) disease.

Curious about what you can drink? 

Well, CaroMont Health says you’ll be able to have:

  • Black coffee
  • Black Tea without milk or sugar
  • Sports drinks such as Gatorade, excluding the red and purple one
  • Lemonade without pulp
  • Sprite
  • Ginger ale
  • Apple juice 
  • Chicken or beef broth
  • Water 
  • Bouillon 

You’ll be able to have these up to 4 hours before your procedure.


So, can you smoke weed before a colonoscopy? No. You’ll need to avoid weed for about 24 hours before your colonoscopy. You won’t be able to have alcohol or tobacco products leading up to your procedure, either. Speak with your doctor about any concerns and get advice on accurately preparing for this necessary procedure. 


About Trevann

Trevann is Stoner Rotation’s Jamaica-based lead writer for the Science section of our cannabis blog. She graduated with honors receiving her Bachelor of Science degree in Molecular Biology from the University of West Indies, Mona. For the last three years, she has covered some of the biggest questions around cannabis and health underpinned with research from supporting studies, medical journals and scholarly articles. Got something on your mind? You can reach her at [email protected].