My 16 year old keeps eating poop out of the toilet. we don't know why? we have to watch him every time he goes and that is impossible to do.

Coprophagia: Eating one's feces may represent severe depression, psychosis or other mood disorders such as schizophrenia, or a medical condition known as pica (when one eats wood, dirt, feces or other atypical substances because of a serious depletion of certain elements in his/her body such as iron deficiency). He should see a physician sooner rather than later.