Trichophagia

Trichophagia is characterized by the person eating hair, usually their own; primarily after pulling it out.

Most often, hair is pulled out and then the ends of the root bulb are eaten, or occasionally the hair shaft itself. 

The hair can eventually collect in the gastrointestinal tract (on occasion, and depending upon severity of symptoms) causing indigestion and stomach pain.

Ritual is a strong factor, and may involve touching the root bulb to the lips, tasting the hair, and occasionally chewing it. 

Sometimes those with the disorder may even eat the hair of others. 

In the psychiatric field it is considered a compulsive psychological disorder. More 

Doctors remove 9-pound hairball from teenager’s stomach