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.
Oil Furnace Costs. The replacement cost for an oil furnace in 2014 averages $5,780 installed. Some installations require additional modifications and can run to about $7,800. Contractors consider the oil furnace when a gas furnace is not possible.