I had cancer of the bladder. First sign was bloody urine. Local hospital did ultrasound and reckoned stones. Referred to Kalasin Govt. hospital. Endoscopy discovered cancer growth not stones witch was removed. I have been having endoscopy check ups every three months for 2 years then 6 monthly now. Each time it has cost me 2,000 baht and done by a qualified English speaking Thai doctor.
I have used both private and public hospitals during my 20+ years in Thailand. The first 10 years my employee provided health insurance at private hospital. After I retired I have been using public hospitals for 10 years. I prefer the government hospitals, a lot less bull<deleted> involved.
So there it is, 2,000 baht, Kalasin Government Hospital., I have receipt if you have any questions. I cant say about colonoscopy.