Volumes of Gas used for colonoscopies.

Air and Carbon Dioxide Volumes Insufflated During Colonoscopy

Author(s) BRETTHAUER Michael ; HOFF Geir S. ; THIIS-EVENSEN Espen ; HUPPERTZ-HAUSS Gert ; SKOVLUND Eva ;

Author(s) Affiliation(s)

The Cancer Registry of Norway Institute for Population-Based Cancer Research, Oslo, NORVEGE

Norwegian Colorectal Cancer Prevention (NORCCAP) Center Department of Medicine, Telemark Hospital, Skien, NORVEGE

Department of Medicine, The Norwegian National Hospital, Oslo, NORVEGE

Section of Medical Statistics, University of Oslo, Oslo, NORVEGE

Abstract

Background: During colonoscopy, air or carbon dioxide is insufflated to secure adequate visualization of the colon, and endoscopy trainees are reminded to use as little gas as possible to avoid patient discomfort. The aim of the present study was to measure volumes of carbon dioxide and air insufflated during colonoscopy.

Methods: Consecutive patients participating in a colorectal cancer screening program were randomized to undergo colonoscopy with either carbon dioxide or air insufflation. Gas volumes insufflated during the procedure were measured with a mass-flowmeter. Four experienced endoscopists performed all of the examinations.

Results: Gas volumes were successfully measured in 218 patients. A mean of 8.3 L of carbon dioxide (range 1.2-19.8 L) and 8.2 L of air (range 1.8-18 L) were insufflated. Mean volumes insufflated per minute were estimated to be 0.26 L and 0.24 L, respectively, in the carbon dioxide and air groups.

Conclusions: The volumes of carbon dioxide and air used during colonoscopy can be estimated. Differences in volumes of gas used by experienced endoscopists were detected.

From Gastrointestinal Endoscopy – 2003, Vol 58, pages 203-206

I came across this Norwegian study in a Medical Journal. The patients were all part of a screening program for colorectal cancer. Usually such patients are sedated and given a muscle relaxant, but they would not have been subjected to intolerable discomfort. I have read that colonoscopies are sometimes unsatisfactory, because the walls of the colon has not been sufficiently distended. In this study, the average volumes used were just over 8 liters and the largest volumes used were 19.8 and 18 liters..

Can anyone explain why the four experienced endoscopists would need to inject such large volumes of CO2 or Air for successful colonoscopy examinations?

Is pressure a factor? Liquids don't change volume under pressure but gas does? I wonder what pressure the volumes were measured at.

Howhamilton said:

[. . . . Can anyone explain why the four experienced endoscopists would need to inject such large volumes of CO2 or Air for successful colonoscopy examinations?

The answer is very simple.

FIRST: Different people have differing degrees of muscle tonus while the gas is being insufflated, so more gas is needed for some than others, but most important the next reason.

SECOND: All the CO2 doesn't stay inside yourself, a good part gets farted out during the procedure because the anal sphincter doesn't retain it all during the abdominal and colonoscope manipulations during insertion and removal, especially when patients are sedated because the muscles (including the anus) are relaxed.

Howie, try taking a big enema and NOT clenching your anus. I bet 1000000000:1 you'll have a mess on your hands, floor, bed or something. Haven't you ever seen a colonoscopy?

Switchablesusie,

Thanks for your expert explanation. I myself have had two colonoscopies which were absolutely painless with NO discomfort, so I needed your explanation.

Thanks, Howard, South Africa.

This is interesting. I do the colonoscopies without the sedation and until now I never realized they used gas of any kind. It does make sense though. Never had a sensation that I was passing gas either. I did wonder why the colon magically moved away from the light and the visibility was much better.

My experience was different from yours. I have had 2 colonoscopies and was put out for both of them. When I woke up I was extremely bloated, gassy and uncomfortable. I don't know how much gas or air or whatever they used but it must have been a lot because I thought I would fart continuously for the rest of my life. They were both done around 8:30AM and I didn't feel even close to normal until the next day. Very unpleasant and they better have a good reason to get me to do that again.

When I had mine, they warned me that when I woke up it was going to be like the fireside bean eating scene from Blazing Saddles.

curious44, how about the threat of colon cancer?

From what I am reading it must be the doctor doing the exam. I had no pain during or after the exam. That includes gas and other forms of midsection pains. I am positive, now, that gas was used because the views were so clear. I have had the same doctor for all my examshat will hurt you; he must be a magical guy. Please do not let me lead you to somewhere that wedeill hurt you. There are people that will not have my expeiences. That is fine. Each of are different.

I am not sure how the post got so screwed up; I am sorry. I think you can read through it.

I am going to be subjected to my first colonoscopy and endoscopy very shortly. I am NOT looking forward to it. I don't like the idea of the prep or the after-effects. I could care less about the procedure itself because I won't know a thing about it given the sedation. The only reason I'm doing it at all is because it's required prior to a kidney transplant. That's my story and I'm sticking to it!

User264, what about the threat of colon cancer? What about it? So far, so good for me. I've had prostate cancer (2006), other than that, nothing yet. Last PSA .4. I'll take that.

Ladydocsin, I hope you find a match and get your kidney. I know 3 people who have had transplants and they're all doing fine. One came from his daughter, the other 2 got lucky finding a match. In fact one of them got lucky twice. A few years after the first transplant this fellow was severely injured in a car wreck and the kidney had to be removed. After recovering from the wreck they found another match and he got a 2nd kidney. Doing fine today. Best wishes to you for the future! Keep us posted. I think it's safe to say this whole site is pulling for you.

Curious,

What about colon cancer? It kills. PSA is no measure of colon cancer risk

Curious - thank you for your kind wishes. I'm at the very beginning of what promises to be a very long road. It seems the medical wheels move much more slowly than I would like them to. My daughter (who is also my best friend) has volunteered to be tissue typed as a possible donor. If she's a match, I will give her plenty of space for her and her husband to weigh their options. If she decides not to donate, no harm, no foul and I go on the wait list until a match becomes available.

I will definitely post updates, probably via my blog. It's been a long strange trip so far, it promises to be even more bizarre as time goes on!

Ladydocisin, I truly wish the best for you. I know the prep is not particularly enjoyable, but it does lead to the truth. May our outcome be wonderful.

Scoping saved my life about 10 yrs. ago. They found a villous adenoma, which was surgically removed. After chemo. & radiation, I've been cancer free since and I get scoped every 3 yrs. looking for more polyps (which they usually find). Yeah, the prep is a real pain, no matter how they flavor it, but after what I've been through, they can scope me every 6 months if they want to.

Lady D. God Bless you! I had no idea of what you are facing. I wasn't religous, but my cancer got my attention and I became a Christian-it's been a great comfort to me. Who knows, maybe some of us on this board will offer prayers for your recovery!

Jimmyt44,

The only thing that turned up in my colonoscopies so far is one benign polyp.

I'm not very religious and don't attend church regularly but I'm definitely a believer and not ashamed to say I turn to prayer and ask for a little Divine intervention now and then myself, especially when it's a health issue and a family member is involved. Once we've been to the doc, what's left?

I had my last colonoscopy about six months ago and without any anathesia. The doctor was infact encouraged since he dosen't like using drugs. As far as pain there was none none at all. I felt inflated and I could feel the tube in me in certain places but it was great in general. The doctor took one small polyp from my ceacum and I felt the tug but no pain. When I was finished they let me go immediately.

Just had one on 8/22/11. No anathesia; one polyp (no clue where), and I felt nothing during removal. As far as gas; I never felt any passing during the procedure. During the subsequent drive to an appointment there was some passing, but not really much more than normal. I have done this before, and this is the first time I recall him going into my small intestine. He did and told me it was healthy.

I am fortunate and happy with the results.....he told me come back in five years.

During a colonoscopy, they usually go slightly (a few inches) into the small intestine so they can look at the ileocecal valve on both sides.