Apart from most guesthouses, hotels and upscale restaurants, squat toilets are the norm. Most of these are located down a dirt path behind a house.
Usually next to the toilet is a cement reservoir filled with water, and a plastic bowl lying nearby. This has two functions: as a flush and for people to clean their nether regions while still squatting over the toilet.
Toilet paper is available at shops all over the country, but not often at toilets. Some places charge a nominal fee to use the toilet.
Sit-down toilets are not equipped to flush paper. Usually there's a small waste basket nearby to deposit used toilet paper.
It's acceptable for men (less so for women) to go behind a tree or bush (or at the roadside) when nature calls.
Buses and smaller boats usually don't have toilets.