My entire adult life I've had a very unstable stomach, and for the past 6-7 years I've experienced pretty much every red flag, but they'd often come in waves - which would give me just enough time to back off from calling my GP.
Last May a good friend of mine, 35 years old, was diagnosed with stage 4 colorectal cancer. He had experienced on/off constipation and stomach pain for a month, but otherwise healthy. When he went to the ER they suspected volvulus, but scans showed a huge tumor blocking. Long story short, it was cancer and it had spread to his liver and lungs.
He's still alive, and responding well to treatment, in the sense that the tumors are shrinking - but in general the prognosis is poor. And he's been completely ravaged by the treatment. If he survives, it is very unlikely he can go back working.
This prompted me to get myself checked. After telling my GP about my symptoms, he told me - yup, better get blood tests, stool samples, and a colonoscopy.
The colonoscopy turned out to be almost completely painless. If anything, the prep was more annoying than the procedure itself. And by far my biggest anxiety was the idea of getting my fears confirmed.
Luckily, there was nothing. Not even a single polyp. All other tests came back normal, too.
So, at least based on my experience, don't hesitate. It's really not bad.
EDIT: I took it without general anesthesia. I was asked if I wanted a mix of sedative and painkiller for the procedure, which I think was some benzo and fentanyl mix - to which I said yes. Where I'm from (Norway), propofol is not the standard for colonoscopy.
Honestly I couldn't really feel much difference when I was given the mix - I've been under general anesthesia before, and the second you get propofol you instantly from normal to "drunk".
Obviously it's individual, though. I've talked with people that have had the procedure without anything (because they had to drive there), and had minimal discomfort. And I've talked with people that needed sedatives / painkillers.
A couple of different stool tests, which look for blood. From what I was told, if these come back positive that alone if enough to warrant a colonoscopy.
To me, it felt like some of the best sleep of my life! The gibberish out of my mouth afterwards thou...well it was a good laugh for my spouse, which is a happy sight seen upon opening my eyes.
Ask for novocain around your external sphincter - there's a high likelihood that the doctors won't think of it, because they're used to doing the procedure on sedated patients - unless, you know, you're otherwise prepared for that experience. That'll take care of ~75% of the discomfort. I otherwise endorse everything you say - it's a fascinating procedure to watch while awake!
It's a low specificity test. If you get a false positive you'll be getting a colonoscopy anyway, and (less of a risk, but still worth considering) if you get a false negative it's a bit of a problem. That's how my gastro explained it, and a bit of my own internet research supported.
At least one decades-old study that had purported to show that the herbicide glyphosate posed no health (esp cancer) risk to humans was retracted in late 2025 (https://www.nytimes.com/2026/01/02/climate/glyphosate-roundu...). Glyphosate may be applied multiple times in a season, both to control weeds but also onto the actual desired crop (i.e. the stuff that gets turned into food for humans and for other animals) as a desiccant a week or two pre-harvest. The official line is that glyphosate that isn't absorbed directly by leaves and other above-ground plant tissues "tightly binds" to soil and is quickly and completely broken down by soil bacteria, though it is also admitted that plant roots can absorb glyphosate and that it can subsequently be transmitted throughout plants. So I would not discount the possibility that some level of glyphosate accumulation in the soil and bioaccumulation in food crops could also be occurring alongside residues from spraying.
In other words, dietary fiber in general or specific forms (e.g. Metamucil aka Psyllium husk) could be effective in lowering CRC risk or could have been so in the past but consumption of real-world dietary fiber in the current era in which glyphosate-based herbicides are in increasingly wide use could now be increasing cancer risks.
I had a family friend who recently passed from colon cancer.
It was particularly brutal because it never showed up in any regular screenings, due to the tumor growing on the outside of their colon. It took ~2-3 weeks just to figure out what it was, but they only knew something was wrong because of some blood tests that came back with unusual results.
It was only 90 days from when they got the call about the unusual results till their death.
Perhaps too much red meat and not enough fiber? "But foods with fiber can have other good effects as well. They can help you stay at a healthy weight and lower the risk of diabetes, heart disease and some types of cancer" https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-h...
To give another perspective on this, all my intestinal issues resolved when I eliminated fiber from my diet. Two other people I very intimately know that had IBS have managed their symptoms into remission by carefully gatekeeping fiber in their diets. last I was deep into this (5yrs ago or so) almost all of the prominent nutritional science was based on survey data and seemed to extrapolate way more than I was comfortable with given the narrow source. I have not kept abreast of new developments, but as far as I know the major impediments to real controlled nutritional studies are the same they always have been.
I started eating Brian Johnson’s superveggie about 4 times a week (it is about a pound of Brokkoli and cauliflower plus lentils and mushrooms) and can only say that my digestions thrives on it after a few days. So at least in my gut something needs to change so it can deal with the huge amount of dietary fiber but once it is settled it makes me feel much better overall
My greater point is that there is no one size fits all here. And generalizing things that are supposed to cover everyone like above is not always helpful, but can be actually harmful.
Fiber is the cause of many of intestinal issues, making constipation and crohn's disease worse.
Red meat also helps people stay at a healthy weight, lower the risk of heart disease (caused by glucose) and some types of cancer (which feed on glucose). What do fiber and red meat have in common? They are not sugar. You could replace fiber with other indigestible material such as sand, the effect would not be much different.
> Fiber is the cause of many of intestinal issues, making constipation and crohn's disease worse.
Big ol' citation needed on that one.
Fiber is more than fine if you actually drink enough water. There are also two types of fiber; some people need one more than the other, or vice-versa.
I know several people with Crohns where fiber has made the biggest difference in controlling it.
> Red meat also helps people stay at a healthy weight, lower the risk of heart disease (caused by glucose) and some types of cancer (which feed on glucose).
Are you a lobbyist for beef? This is not at all what research says, and research has said mostly the opposite for decades.
I had some concerning digestive issues a few years ago at 36. Tried repeatedly to get a colonoscopy done, but was told I was too young. Fought with my doctor for almost a year to get a referral to a specialist (standard procedure in Canada). Then had to fight the specialist to finally order a colonoscopy. I finally had enough and lied about blood in my stool to get one. Luckily the digestive issues turned out to be stress related and nothing serious, but guess what they found during the procedure?
3 pre-cancerous polyps! Might have saved my life, as the recommended age for first screening here is 50! I'm now on a schedule to get checked every three years.
dudes, colonoscopies hurt less than going to a dentist for a cavity. The prep is the main thing that sucks because the stuff tastes like ass but hold your nose and chug. Easiest test you'll ever have and could save your life.
Paywall so I couldn't read, they probably mention this: Eating more fiber (to a point of course) will decrease your risk of colorectal cancer. Most westerners, especially americans, are eating about half the recommended amount of fiber. Could certainly be a contributing factor.
My entire adult life I've had a very unstable stomach, and for the past 6-7 years I've experienced pretty much every red flag, but they'd often come in waves - which would give me just enough time to back off from calling my GP.
Last May a good friend of mine, 35 years old, was diagnosed with stage 4 colorectal cancer. He had experienced on/off constipation and stomach pain for a month, but otherwise healthy. When he went to the ER they suspected volvulus, but scans showed a huge tumor blocking. Long story short, it was cancer and it had spread to his liver and lungs.
He's still alive, and responding well to treatment, in the sense that the tumors are shrinking - but in general the prognosis is poor. And he's been completely ravaged by the treatment. If he survives, it is very unlikely he can go back working.
This prompted me to get myself checked. After telling my GP about my symptoms, he told me - yup, better get blood tests, stool samples, and a colonoscopy.
The colonoscopy turned out to be almost completely painless. If anything, the prep was more annoying than the procedure itself. And by far my biggest anxiety was the idea of getting my fears confirmed.
Luckily, there was nothing. Not even a single polyp. All other tests came back normal, too.
So, at least based on my experience, don't hesitate. It's really not bad.
EDIT: I took it without general anesthesia. I was asked if I wanted a mix of sedative and painkiller for the procedure, which I think was some benzo and fentanyl mix - to which I said yes. Where I'm from (Norway), propofol is not the standard for colonoscopy.
Honestly I couldn't really feel much difference when I was given the mix - I've been under general anesthesia before, and the second you get propofol you instantly from normal to "drunk".
Obviously it's individual, though. I've talked with people that have had the procedure without anything (because they had to drive there), and had minimal discomfort. And I've talked with people that needed sedatives / painkillers.
Which tests did you have run?
A couple of different stool tests, which look for blood. From what I was told, if these come back positive that alone if enough to warrant a colonoscopy.
I had United Healthcare PPO and I got hit with a $3000 bill for the colonoscopy because of the conveniently out of network anesthesiologist anyway.
If you are avoiding a colonoscopy because you don’t want to get knocked out, they can do it while you’re awake.
If for some reason you don’t want to be anesthetized you can just ask. It is also cheaper this way and you can drive yourself home.
Based on my limited research it seems like anesthesia is mostly there because people are prude.
The painful parts of procedure doesn’t hurt any more than having bad gas pain.
And it’s only a few less-than-ten-second points during the procedure that are anywhere near what I would describe as painful.
The insertion of the camera is rather jarring if you’re not used to having things stuck up your ass, but again surprisingly painless.
I was able to watch along with the doctor on a massive tv screen and see my own innards.
Worst part was taking preparatory laxatives before.
Overall not a bad experience for the piece of mind it provided.
Get a colonoscopy if you are due or have reason to believe you should get one.
Actually the greatest thing for me is the falling asleep effortlessly part!
To me, it felt like some of the best sleep of my life! The gibberish out of my mouth afterwards thou...well it was a good laugh for my spouse, which is a happy sight seen upon opening my eyes.
Ask for novocain around your external sphincter - there's a high likelihood that the doctors won't think of it, because they're used to doing the procedure on sedated patients - unless, you know, you're otherwise prepared for that experience. That'll take care of ~75% of the discomfort. I otherwise endorse everything you say - it's a fascinating procedure to watch while awake!
I think most people are not used to having things stuck up their ass.
That's an incredibly easy thing to change. It takes little money, a flared base, and only mild curiosity.
Lol. “Most” is doing a lot of work there.
How about DNA based stool tests instead of colonoscopy?
It's a low specificity test. If you get a false positive you'll be getting a colonoscopy anyway, and (less of a risk, but still worth considering) if you get a false negative it's a bit of a problem. That's how my gastro explained it, and a bit of my own internet research supported.
At least one decades-old study that had purported to show that the herbicide glyphosate posed no health (esp cancer) risk to humans was retracted in late 2025 (https://www.nytimes.com/2026/01/02/climate/glyphosate-roundu...). Glyphosate may be applied multiple times in a season, both to control weeds but also onto the actual desired crop (i.e. the stuff that gets turned into food for humans and for other animals) as a desiccant a week or two pre-harvest. The official line is that glyphosate that isn't absorbed directly by leaves and other above-ground plant tissues "tightly binds" to soil and is quickly and completely broken down by soil bacteria, though it is also admitted that plant roots can absorb glyphosate and that it can subsequently be transmitted throughout plants. So I would not discount the possibility that some level of glyphosate accumulation in the soil and bioaccumulation in food crops could also be occurring alongside residues from spraying.
In other words, dietary fiber in general or specific forms (e.g. Metamucil aka Psyllium husk) could be effective in lowering CRC risk or could have been so in the past but consumption of real-world dietary fiber in the current era in which glyphosate-based herbicides are in increasingly wide use could now be increasing cancer risks.
I had a family friend who recently passed from colon cancer.
It was particularly brutal because it never showed up in any regular screenings, due to the tumor growing on the outside of their colon. It took ~2-3 weeks just to figure out what it was, but they only knew something was wrong because of some blood tests that came back with unusual results.
It was only 90 days from when they got the call about the unusual results till their death.
Perhaps too much red meat and not enough fiber? "But foods with fiber can have other good effects as well. They can help you stay at a healthy weight and lower the risk of diabetes, heart disease and some types of cancer" https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-h...
To give another perspective on this, all my intestinal issues resolved when I eliminated fiber from my diet. Two other people I very intimately know that had IBS have managed their symptoms into remission by carefully gatekeeping fiber in their diets. last I was deep into this (5yrs ago or so) almost all of the prominent nutritional science was based on survey data and seemed to extrapolate way more than I was comfortable with given the narrow source. I have not kept abreast of new developments, but as far as I know the major impediments to real controlled nutritional studies are the same they always have been.
I started eating Brian Johnson’s superveggie about 4 times a week (it is about a pound of Brokkoli and cauliflower plus lentils and mushrooms) and can only say that my digestions thrives on it after a few days. So at least in my gut something needs to change so it can deal with the huge amount of dietary fiber but once it is settled it makes me feel much better overall
Its a good perspective, however perhaps your body just cannot deal with a higher amount of fiber compared to others.
In the same way that diabetics need to tightly control their sugar intake, it doesn't mean therefore that need for sugar is up for debate.
My greater point is that there is no one size fits all here. And generalizing things that are supposed to cover everyone like above is not always helpful, but can be actually harmful.
I found a big difference between soluble (trouble for me) and non-soluble fiber (okay, within limits).
that isn’t new however
Fiber is the cause of many of intestinal issues, making constipation and crohn's disease worse.
Red meat also helps people stay at a healthy weight, lower the risk of heart disease (caused by glucose) and some types of cancer (which feed on glucose). What do fiber and red meat have in common? They are not sugar. You could replace fiber with other indigestible material such as sand, the effect would not be much different.
Dietary fiber is a great way to reduce colorectal cancer risk: https://www.sciencedirect.com/science/article/pii/S266615432...
> Fiber is the cause of many of intestinal issues, making constipation and crohn's disease worse.
Big ol' citation needed on that one.
Fiber is more than fine if you actually drink enough water. There are also two types of fiber; some people need one more than the other, or vice-versa.
I know several people with Crohns where fiber has made the biggest difference in controlling it.
> Red meat also helps people stay at a healthy weight, lower the risk of heart disease (caused by glucose) and some types of cancer (which feed on glucose).
Are you a lobbyist for beef? This is not at all what research says, and research has said mostly the opposite for decades.
I had some concerning digestive issues a few years ago at 36. Tried repeatedly to get a colonoscopy done, but was told I was too young. Fought with my doctor for almost a year to get a referral to a specialist (standard procedure in Canada). Then had to fight the specialist to finally order a colonoscopy. I finally had enough and lied about blood in my stool to get one. Luckily the digestive issues turned out to be stress related and nothing serious, but guess what they found during the procedure?
3 pre-cancerous polyps! Might have saved my life, as the recommended age for first screening here is 50! I'm now on a schedule to get checked every three years.
I've found it helpful to knock down a glass of metamucil (Psyllium Husk) morning an night most days where I can.
dudes, colonoscopies hurt less than going to a dentist for a cavity. The prep is the main thing that sucks because the stuff tastes like ass but hold your nose and chug. Easiest test you'll ever have and could save your life.
Paywall so I couldn't read, they probably mention this: Eating more fiber (to a point of course) will decrease your risk of colorectal cancer. Most westerners, especially americans, are eating about half the recommended amount of fiber. Could certainly be a contributing factor.
Processed foods and sleep deprivation!