RED DEER, Alberta -- Hairballs aren't just a problem for cats; they can affect people, too.

After surgeons removed a grapefruit-sized hairball from the stomach of a 3-year-old Canadian girl, her mother said she wants to warn other parents about the developmental disorder that causes children to munch on their hair.

Pica is a behavioral disturbance in which people -- often young children -- persistently eat nonnutritive substances, such as clay, dirt, or hair. While this is developmentally normal for a child who is 18 to 24 months old, it can be serious if it lasts significantly longer than a month.

Pulling out hair and eating it is a combination of pica and trichotillomania, in which people -- often young girls -- repetitively pull their hair out at the root from places like the scalp, eyebrows, or eyelashes, sometimes causing baldness. The condition is poorly understood.

The result can be that hair gradually builds up and entangles into a ball within the stomach, known medically as a trichobezoar.

Cherie Trahan, the girl's mother, said the toddler not only ate hair, but string and the stuffing from her stuffed animals.

Trahan says her daughter is doing well after the surgery and is gaining back some of the weight she lost. But the family isn't taking any more chances. They've cut the girl's hair short.

Additional Resource:

• Emedicine.com: Pica