"18 month old Daughter finds releasing her bowels scary"

My Daughter has been having problems with her bowels since we came back from India in November 2010. After several weeks of uncontrollable bowel motions she lost so much weight i continued going to GP's, Walk-in centres and the Hospita. After running tests they advised she is lactose intolerant so i have kept her lactose free up until March.

Since then every time it comes to having a poo she tries to stop it and screams and cry's and she tenses up. If she is laying down she goes in to a press up position and does not liked to be touched. I have been to our GP again but we're given nothing except for lactulose to soften the stool but this does not help.

I don't know what to do and how i can change this for my daughter. On the 4th day her stool comes out like a small ball and is very hard and smelly.

Please help, she seems as if she is in pain as well as being scared.