Avoid giving laxative during school days. Instead, give them veggies, fruits and lentils with high fiber to aid bowel movement.
For now it will be easier on the teachers if the girls went to preschool in pull ups.
And hold strong ..... other people don't necessarily know what you and the girls have gone through in the last 3 years. Look at the bright side that despite being premies, they are going to preschool at the same age as other kids! Expect these accidents as normal behavior for them.
I had my twins 5.5 weeks early and they are now 3 years and 3 months. Mine had diet, texture and allergies issues as well, but they have recently outgrown most of them .... so let me share some fiber recipes with you:
Broccoli & cheese: I steam the brocolli in a pressure cooker. Add grated cheddar cheese and mash the two together. Serve warm. You can substitute with cottage cheese which is low in lactose and add a pinch of salt to it.
Sweet potato & carrots: I steam 4 long carrots and 1 medium sweet potato in a pressure cooker with just a little bit of water. Mash them and serve warm .. its sweet.
Carrot & peas: Steam frozen carrot & peas in a pressure cooker with garlic powder, lemon pepper salt. Serve warm with whole wheat bread.
Oatmeal and cornflakes with lactaid milk and frozen blueberries or strawberries. Microwave 1.5 cups of milk in glass container (I use a large measuring cup) for 2 minutes. Let berries stay in warm milk for a few minutes, mash them before putting oatmeal and cornflakes in it. Let sit for 10 minutes so oatmeal gets mushy.
Cook lentils in pressure cooker with plenty of water. Add sauted medium onion, garlic powder, any herbs (fresh or dried), some spices, salt to taste. Serve with rice or whole wheat bread or simply as a lentil soup.
Lactaid yoghurt: make yoghurt from lactaid milk. Boil the milk and let cool in a pottery or glass container to just warmer than room temperature. Add active cultures yogurt in it (1 large spoon for every cup of milk). Cover and wrap in a towel and let sit for 8 hours in the oven (overnight). Take out from the towel and put in fridge for a couple of hours ... use within a few days. Remember to keep some home-made yogurt aside to make your next batch of yogurt.
Good Luck with the potty training efforts ... one day it WILL happen!