We live about 45 min north of Atlanta. My son is four (not close to the ages you have) but I would love to find out where you eat and what you buy. There is also a 7 yr old girl that lives close to us that was diagnosed in April.
My 4 yr old's poop was green too. When we eliminated lactose, that got better within a week. I was anxious about reducing his diet again (since going gluten free). SOME (not all) GIs will allow you to give your child a lactaid tablet before feeding your child lactose. We have switched to lactose free regular milk and lactose free yoplait yogurt. Both are very good and my son will tolerate them. However, cheese was disgusting. We choose to eliminate cheese for the meantime. It is also important to remember different food have lesser amounts of lactose - hard cheeses and yogurt are easier for those that have an issue digesting lactose. One big side effect of difficulty digesting lactose is green poop.
My son was diagnosed by endoscopy almost 3 weeks ago. We noticed a change after about 2-3 days. His abdomen was less bloated within 1 day. He was running and playing instead of sitting on the couch and watching t.v. We are almost 3 weeks in and his belly still hurts, but pain is less severe and he is much more active.
Unfortunately, he wants us to stay away from fructose and sucrose. I called my ped gi today and demanded I speak to someone that could help me. I received a call from the head of nursing who was VERY HELPFUL. He told me that since my son's gut was very sick they wanted to take out everything that would trigger a reaction (and also because he tested to positive to the lactose and sucrose test - still not sure what the test is called). He told me to first take out lactose and then call him back in a week to see how my son was doing. If I was seeing steady improvement, then we could think about just doing lactose free for another week. He said that when I start sucrose, I need remove as much as possible but it's not like gluten (a little sugar won't hurt him) He told me to focus on removing table sugar and limit fresh fruit to only once every few days. I'm relieved my son can have small amounts of sugar.
I just want to do everything perfect. I feel like I'm slowly getting this gluten free diet, but too much too soon is scary. I'm also feeling pretty confident about lactose free since my son drank a full glass of lactose free milk and didn't notice. Thanks for the support. This group has been so helpful through this scary transition. I can't wait for my son to start gaining weight and playing like his friends.