Re: Enema for a 9 YO
This was probably the best possible outcome for the child. A third party like a visiting nurse can often better achieve success in a situation like this than can a parent who has been involved in emotional battles over severe constipation with the child.
In the future, along with the recommended dietary program, I would also suggest that your niece encourage the child to become involved in activities that promote physical exercise. Children who sit around the house are far more likely to experience constipation and develop impactions than their more active peers.
As unyquity posted above, constipation can become a very serious problem with children if not corrected quickly. I blame the medical profession for telling parents not to worry about their childrens bowel habits, and that one bowel movement a week is normal for some. I totally disagree.
In the future I recommend that your niece not let the child go more than 2 or 3 days at the most without a bowel movement before intervening. Some people can develop a fecal impaction in this short time, and when this happens, removing it is always uncomfortable and can be traumatic, especially for someone that age.