The problem is that diagnostics aren't necessarily risk-free. For example, there's a non-zero risk of death while getting a colonoscopy, to the point that false positives from unnecessary testing can increase all-cause mortality for patients.
Late 20's Hispanic lady shows up in the ER with what they think is probably food poisoning. But they do a CT. Which shows changes in her liver which probably is a fatty liver. But they do a biopsy just in case. Biopsy results in a bleed which requires a transfusion and 4 days in the hospital. Biopsy result, fatty liver.
Surprisingly few ER docs anywhere in the world have even a rudimentary understanding of the risks of CT scanning patients. There's a lot of information around about this, but my own first hand (anecdotal) experience is that I've had ER docs try to convince me that it's basically the same as an X-Ray and act like I'm a crazy person when I explain that it's orders of magnitude higher and cumulative over a lifetime. On one hand, it's not their job to care about your long term health - they need to rule out an emergency and get you out the door as quickly as possible - but it's very concerning.
It's a bit like how general practitioners aren't taught about nutrition at all, so give out really poor advice for heart disease patients (the leading cause of mortality in Western economies).
https://en.wikipedia.org/wiki/Linear_no-threshold_model
Edit: For comparison, a chest X-ray is around 0.1mSv, a chest CT at 6.1mSv, so a factor of 61 between (https://www.radiologyinfo.org/en/info/safety-xray ). Compared to natural exposure (usually 1 to 3mSv/a) however, a chest CT isn't that bad at 2 to 3 years natural dose, 2 polar flights or 1 year of living at higher altitude or Ramsar (https://aerb.gov.in/images/PDF/image/34086353.pdf ). Acute one-time dose damage has been shown above 100mSv, below that there is no damage shown, only statistical extrapolations.
So I'd say that the risk of using a CT right away should be lower than the risk of overlooking a bleed or a clot in an emergency, where time is of the essence and the dance of "let's do an X-ray first..." might kill more patients than the cancers caused by those CTs.
Yeah, but what's the alternative when you have a stroke? They need to understand it's type and the mistake here is likely to be fatal since they require opposite treatments.
Turns out, I needed to go to the bathroom frequently during the day which was an annoyance but I never had anything close to an "accident" nor did I feel any strong urge to evacuate at night. So the whole experience turned out to be a huge nothing-burger and I had a few polyps that got sniped that weren't cancerous - so now I have peace of mind that I didn't have before.