There are some mumsnetters who seem to have little understanding of basic internet safety. Its not all scams trying to steal your money.
On public forums, and mumsnet is one, there will be men lurking who like to wank over details of children's bodies. That includes teenage girls having periods, details of puberty, poo accidents.
If someone is asking for help you can give them advice without talking about your own children's bodies and/or experiences. So you can reply - this is a common issue, you should go to your GP and get it checked out, but unlikely to be anything to worry about. Rather than - yes my 7 year old DD had this ...followed by details about her body and issues.
Please remember this is a public forum. Anyone can read it, not just those registered. So please remember internet safety and don't share wank material about your children.