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.
How long does the charcoal last / burn? Since lump charcoal is very responsive to oxygen, the burn time varies greatly based on the circumstances. On an open picnic grill, you will get about 45 minutes. In a closed off and air regulated smoker or a ceramic Kamado type grill, the coals will last anywhere from 3-4 hours.