I think in reference to a child possibly suffering from sexual abuse if they are wetting their pants or bed is a little different from what you think. It is in reference to child who are toilet trained who then suddenly revert back to wetting their pants/bed. This can sometimes be a physical sign of children who have been sexually abused. It is not in reference to children who are not toilet trained and it is not in reference to all children.

In regards to the masturbation it is also in reference to children who masturbate excessivley (ie in front of other people, continue to do so after redirection, try to coerce other children to join in). This is often another sign of possible sexual abuse. Child psychologists and other experts have outlined normal sexual development of children as a guideline and any differences in sexual development for a child's age may need to be looked at further.