My two year old has just started preschool and he wakes up crying in the night. I am worried something is wrong at school. What should I do?

May be something is irking him at school or he is not getting used to the environment. It would be a better idea to discuss it with the school teacher. May be you find a clue. I found this article helpful. http://www.huffingtonpost.co.uk/2009/12/10/checklist-is-your-child-unhappy-at-school_n_7404152.html