my brother had this exact same problem at approximately the exact same age. Please take some comfort in the fact that he did outgrow it & is a happy, well adjusted adult. First check with pedi, what is Dr's opinion? my mother & dad would go in the bathroom with John a couple of times a day. Play a radio softly, bring a book. take deep breaths and encourage your little girl to relax and breath. while she sits on the toilet, you can occupy her with the book or with small talk. While OFF the toilet, explain how holding BM's in- can cause them to get hard and give her aches. The 1st time a child is constipated & has pain with a bowel movement- they will get anxious. letting her know that she has the POWER to control this might give her a sense of security. she will be relieved to know that this happens to others sometimes and "Just take it easy" I hope this helps, good luck to you. I myself am a mother and I'm sorry that you all are going through this, but as I said in the begining- I watched what being relaxed and patient can accomplish. hang in there!