My 5 yrs old son s stool is grey and white. It s started with a yellowish liquid stool and now it s a more normal looking but whitish grey.....should I worry because he feels fine. Also, he was born with a kidney problem that they operated him when he was 8 months old because he was loosing it and also he doesn t eat much food.....no meat, no vegetable( only carrots and cucumber), apples, banana, peanut butter made with soy bean , hot dog, pasta( only white or with cheese) cereal lucky charms and 1 slice of Kraft cheese a day. Please let me know if I need to worry thank you.