Surgery - Colorectal. In brief: Yes, most docs can. Most hemorrhoids should first be treated by conservative measures, such as bulking the stools, education to avoid bad habits like straining, sitting for long periods of time, etc.
Either system will have a burner. 23 years may very well be beyond the typical life expectancy of a oil burner, but a furnace or boiler should last considerably longer than 23 years. The boiler of my house here in MA is 58 years old and still works fine. I am starting to consider replacements, however.
Typically, though, furnaces will last 15 to 20 years, while boilers can last up to 30 years, depending on the quality of the water supplied to the system. Proper maintenance of your central heating system includes regular inspections and cleaning by a licensed technician.