I've read that in Thailand there are a lot of 7/11 shops where you can buy all kinds of milk. But what happens in Laos? Is it easy to find milk in Laos? (more concrete: UHT milk).
Judging by the cost of living charts for Laos, milk is not particularly expensive, indicating it's probably not hard to find and not rare, even if a lot of the locals are lactose-intolerant, it's readily available in supermarkets.
Evidence of this is found in a blog about this very topic where they indicate that certainly in Vientiane, milk is available in supermarkets, and there's no reason to indicate there should be a problem anywhere else.
As for UHT milk, it's certainly available in Vang Vieng, as evidenced by this blog & photo, so again, should be available elsewhere.