How is her diet? Does she get any fiber? Most children do not drink enough water. McD's Happy meals can be lethal.;) Has the child been seen by a pediatrician? preferably a pediatrician that specializes in gastrointestinal issues.
You write that her symptoms include 'weird feelings' in her vagina, urinary problems.
These can be symptoms of sexual abuse. I suggest that you sit down with her in a quiet place where she feels safe. Have a discussion about "Good Touch/Bad Touch"? Assure her that she can tell you anything. Even if someone has threatened her or those she loves. Even if nothing improper has happened to her, she may open up and reveal some useful information.
Please do not subject the child to a colonic. How about a good old fashioned remedy...a dose of mineral oil a fews times a week. Have her eat a daily cup of Activia yogurt.