These countries have the wealth that India does? I'm asking because I honestly don't know not trying to prove anything. I guess I'm speaking relative to population size.
As I understand it, the problem in India (and these other places) is more infrastructural than wealth-related. I was reading a UN report on this, which is where I got that claim from. I'll try and dig it up. The argument was basically that if money was channeled into these public infrastructure projects, the problem would pretty much disappear, but currently there's corruption and general apathy towards the condition of the poor that's preventing it. Closed sewers and simple toilets aren't really that expensive, from what I know.