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.
Law of Averages. Today's furnaces can easily operate for 20-30 years, though the average life expectancy is 16-20. How often your furnace is used determines wear and tear to parts involved in starting and stopping the system, such as fans and electronic ignitions.