I have three kiddies with lactose intolerance.
for them, anyhting with a high milk content is a no no, but some things only cause probs with 'build up'.
for them they have....
soya milk for drinking
soya ice cream...the swedish glace one (I buy it in tesco, but I think it is avaliable most places). it is very creamy and I even prefer it to 'normal' ice cream.
soya yoghurts...provamol are the best and nicest. you can have a dessert form found in the free from aisle or there is a fresh yoghurt in the chilled section.
mine can tolerate tho......
chocolate
milk in mashed potato
milk in a drink (they like hot chocolate but soya in hot drinks tends to curdle)
cheese pizza
and as long as they don't have too many, they can also eat fromage frais.
butter on toast/in sandwiches
butter/milk/dairy in biscuits/cakes/pastry goods
they can and do suffer from build up tho at least once a month (two months in the girls cases....tis DS2 who is the worst effected now!), and so they then have to avoid any and all forms of milk for about a week.
HTH...and good luck. it isn't as bad as it sounds, and very easy once in the swing of it all. Ice cream avoidance is the hardest now for mine in the summer, but it is easily remedied with a bit of afore thought.