Are colonoscopies worth it?

Clearly they mixed up cause and effect.

"A gentleman's hands are never dirty" should have meant that he keeps them clean, not that his gentlemanliness somehow keeps them from being dirty.

> Doctors routinely washed their hands before Semmelweis

The cringeworthy "gentlemen don't wash their hands" culture contradicts that.

> he ended up in a sanatorium because he went crazy (he likely had an advanced case of syphilis)

I see no evidence of this so called "craziness". Even the people who speculated about the cause included "emotional exhaustion from overwork and stress" as a possibility. That's the simplest explanation, probably what happened and it's absolutely to be expected when you discover you've been unwittingly killing your patients due to the ignorance of mankind, successfully devise countermeasures and prove their effectiveness only to have your peers and the scientific community all band together to gaslight you. He ended up in an asylum because he "embarrassed" them.

> the connection he made was that "cadaveric particles" were causing illness in hospitals

Of course. More women died when he and his medical students delivered their children after working with corpses than when they didn't. The connection is there, the fact it did not fully explain the phenomena does not invalidate it. Nor does it invalidate the reduction in mortality after hand sanitization was implemented.

That this was denied despite reproducible statistical evidence is absolutely shameful for all involved and a heavy lesson for all time. Women died because of it. Don't minimize it.

I've seen a doctor literally commit suicide when faced with the mere possibility that he caused harm to another human being.

Bright red "live" blood can come from any part of the lower intestines. Strong-smelling feces with dark blood are called melena and are associated with bleeding in the upper gastrointestinal tract, peptic ulcers are a common cause. The reason for the difference is the blood gets digested as it passes through the gastrointestinal tract. It's not a 100% exact science, bleeding in the lower intestines might still spend enough time in the body to be digested and bleeding in the upper gastrointestinal tract might come out fast enough that it still looks red. Additional symptoms usually provide enough context for a clinical decision to be made.

> fecal occult blood test

Often used to screen patients for colonoscopies. Screening is looking for disease in the asymptomatic: "occult" means it's not visible to the naked eye, you're looking for blood even though the patient has not noticed any. The symptomatic don't need screening, they need diagnosis and thus proceed directly to colonoscopy. Or endoscopy if upper gastrointestinal tract bleeding is suspected.

- In assessing risks vs. benefits, it isn't sufficient to use a single figure (e.g. 5-year relative survival rate). It's not binary. Screening which detects potential cancer does not just prevent death. It prevents the suffering and disability which may accompany late-stage detection (even if you're still alive after 5 years). Early detection could have prevented the two surgeries and rounds of chemo a friend of mine went through. Or the death of another friend after 3 rounds of surgery and 2 rounds of chemo. It could prevent living the rest of your life without normal bowel function.

Figures can't capture individual assessment of risk/benefit. Many of us buy insurance of various kinds even though the insurance companies have done some figures and expect to make money - in fact, they count on us valuing certain things above what is indicated by the raw numbers.

- The NordICC study [0] is cited by some as showing modest benefits from colonoscopies. It looks pretty good, but there's something I don't understand. They say: "Follow-up data were available for 84,585 participants in Poland, Norway, and Sweden — 28,220 in the invited group, 11,843 of whom (42.0%) underwent screening, and 56,365 in the usual-care group. A total of 15 participants had major bleeding after polyp removal. No perforations or screening-related deaths occurred within 30 days after colonoscopy." Given the number of screenings, I don't see how there could be no perforations. For example, the USPTF study [1] (see their "Supporting evidence" link) reports 5.4 perforations per 10,000 colonoscopies from colonoscopy to follow-up positive screening results and 3.1 perforations per 10,000 colonoscopies from screening colonoscopy. No perforations seems unrealistically low - maybe someone can explain this.

- Discomfort from the prep or procedure depend on the individual, and I don't think one can usefully generalize. I've had 4 colonoscopies, the first two with sedation and the last two without. I had 3 polyps removed the first time, none during the second, 2 polyps removed during the third, and none during the fourth. The advantages of no sedation are that I don't feel groggy afterward, and I can drive myself to and from. The procedures without sedation felt no worse than a bad case of gas (not surprisingly!). I watched the polyp removal during the third colonoscopy and didn't feel anything above the ambient gas pain. But some people might find the procedure very painful, or might get queasy watching. Everyone's different. And if you start without sedation and decide you want to stop in the middle, they might abandon the procedure and require you to come back again (in which case insurance is unlikely to pick up the second try). If you have one of these done with sedation, you might find it interesting to look at the itemized insurance docs and see how much they charged for the sedation (often done by an outfit independent from the GI practice). As for prep, the miralax with Gatorade is much better than the old stuff (which is damning with faint praise).

[0] https://www.nejm.org/doi/full/10.1056/NEJMoa2208375 [1] https://www.uspreventiveservicestaskforce.org/uspstf/recomme...