WWYD?: Temporary lactose intolerance

I decided I should start a special category for questions for which I have no answer. Since I'm turing it over to you, the readers, I'm going to call this category "What Would You Do?". If you have any experience with this, please weigh in in the comments.

Janie writes:

"My 10-month old son has had diarrhea for 18 days now.  (Don't worry - he's not dehydrated and I have had him checked by two pediatricians!)  Over the weekend I was finally able to conclude (with the help of my U of Google MD) that he is suffering from temporary lactose intolerance.  It seems he had a virus or something in the beginning, and now that is gone, but his intestines were damaged such that now he can not tolerate milk products.
I nursed him for 9 months, he spent at least one month on the milk-based formula with no problem, he then suddenly developed diarrhea and we put him on Isomil DF (soy-based).  Once he improved, at the doctor's suggestion, I re-introduced his regular formula (half and half with the DF).  Within 24 hours he had awful diarrhea again.  Went back to soy formula only, and the problem is resolving.
Of course, the doctor's office has not been very helpful - we actually switched pediatricians over this when the first one just told me to wait the diarrhea out (on day 11!).  The second doctor is much more caring and agrees that this sounds like temporary lactose intolerance.  I plan to keep him on soy formula for 4-8 weeks while his intestines heal.
So, my question is - do you or any of your readers have any experience with this?  I am finding it unnerving - I am happy to finally know what is causing the diarrhea, though, because that was quite scary for me and very unpleasant for the baby.  He developed a horrible burn-type diaper rash which has now receded, thankfully.
I guess I'm just looking for advice, support, personal experience with a lactose-intolerant child.  I am particularly sad because the baby loves cheese and now his diet must change so much."

Oof. Your poor little guy. It's good you were able to nurse for as long as you did, or the problem might have been even worse. And how about you for figuring out what was going on! Yay, Tiger Mama.

I've got nothing for you here except that of course you know he'll be fine and perfectly healthy even if he can't have milk. He may be able to tolerate yogurt, but even if he can't for awhile (or ever), he'll still grow up normal and healthy.

Now, readers. Anyone else have any experience with this? Or just with having to put a baby/toddler on a restricted diet? Any advice for weathering this?