The details about the situation with the war is confusing, vague, and scanty.
He mentions that the "city" (tiny town) was "blockaded" and that the "enemy" held the suburbs around so they couldn't get into the woods to get firewood. And that they fought the "enemy" and held the town against them. But there was no army in the town. Futhermore snipers (of the "enemy"?, the gangs?) made the streets dangerous to move about.
There were situations in the Bosnian War when towns were in cauldrons, not really single towns, and the encirclements encirled military forces inside... And frankly why would an army not just move into a town? Because usually there is another army holding it against them. If they are empty of such, tiny groups of unorganized men won't hold it.
Maybe it happened in times of cease fire, because there were long pauses in the war. Time spent at the table negotiating. In the country, on the field, it just meant they did not make organized offensives against each other, taking potshots and throwing couple of grenades just for kicks is another thing. So the "sniper" story might be plausible, but not able to move around, liek going to other towns because completely cut off, or incapable of gathering wood sounds bs. Similarly not having authorities organizing, offering services, like medical ones, or not having radio(! wtf?!) or news... Load of nonsense.
Reverting back to medieval times - in the sense that having tap water or constant electric supply is a thing they had to miss out on - is also likely. But I'm pretty sure they still had old style gravitational toilets in every other garden. So shitting into catholes must had been a very occasional activity.