its funny theres no type of toilet anywhere, even in big cities like solitude...makes you wonder what they do with number 2

Theres even a manhole in solitude that makes sewer noises but like you said, whats it for? To wash the poo from the street?
If you are saying there are no toilets, as in the modern plumbing and porcelain version, then you are correct.
But if you are saying there are no toilets, as in lavatories - places for people to defecate, then that is incorrect. There are plenty of houses in the cities where you'll find buckets and small stools tucked into a corner or in a very small seperate room. Even bandit caves usually have seperate pits with a bucket in them.
Bethesda's attention to detail in this particular case is quite nice in my opinion, I theorize the idea is everyone defecates in a bucket then either throws it out on the street or into a sever grate if one is available. Which coincidentally is pretty much how it worked before in many places in real life.