Pica is a rare disorder, which makes the sufferer feel a compulsion to eat non-food items. And once It starts, it can be difficult to control.Common cravings include the urge to eat soil, coal, rust chalk and paper. Sufferers have also been known to ingest animal feces and bits of metal. A US study found 25% of psychiatric patients and 60% of people with autism had pica. The disease usually appears in people of a low mental age. Many doctors believe that pica could be a sign of  deficiency of some nutrients especially iron.

Sufferers eat what is edible but - not  but not prepared for eating, like coffee powder or potato peelings.

The sufferers eat anything.

Infants and toddlers who eat a non-food item repeatedly for more than a month could be suffering from pica. Most infants however outgrow it by the age of two 40% of pregnant women experience cravings, a small proportion of which are for non-food items

Hospital authorities report women craving coal, chalk, even cigarette ash However, usually only occurs In early stages and goes away

In 2002, a a-year-old French man went to hospital complaining of stomach pains. An x-ray showed he had swallowed 5 kg of coins necklaces and needles; his stomach was so heavy It had been forced down between his hips. He died after an operation to remove the objects

Pica is a peculiar disease that causes people the urge to eat soil, rust, coal, chalk and paper. Although people have been known to ingest anything from animal feces to bits of metal. Pica appears in people with low mental age, people who show learning disabilities. There have been cases with people who have eaten chains, bones, buttons, rubber and so on and have to be taken to the operation theatre for operation.

It is a typical condition when strted is very difficult to control. Young Children show signs of this disease but as they grow they stop this behaviour at the most by the age of 2. In pregnancy also the signs of pica have been seen. Women crave from chalk to cigaratte ash during the early periods of pregnancy. Although research on the topic is still on doctors say that it is caused by the deficiency of some nutrients in the body.

Pica in children, while common, can be at times dangerous. Children who eats  plaster containing lead may suffer brain damage from lead poisoning. There is a similar risk from eating dirt near roads that existed prior to the phaseout of tetra-ethyl lead in gasoline or prior to the cessation of the use of contaminated oil (either used, or containing toxic PCBs) to settle dust. In addition to poisoning, there is also a much greater risk of gastro-intestinal obstruction or tearing in the stomach. This is also true in animals. Another risk of dirt eating is the possible ingestion of animal feces and the accompanying parasites.

Know more about pica by reading en.wikipedia.org/wiki/Pica_(disorder)

If pica is a lifestyle choice that does not harm the individual, and if it is not part of an underlying eating disorder, it can go untreated, but care should be taken to protect against toxic substances such as lead in paint and plaster chips. The person must be alert for symptoms (pain, lack of bowel movements, abdominal bloat and distention) that suggest the substance has formed an indigestible mass that has blocked the intestines. If such is the case, immediate medical attention is necessary.

Pica is a pattern of eating non-food materials (such as dirt or paper). This pattern should last at least 1 month to fit the diagnosis of pica. Causes, incidence, and risk factors.  Pica is seen more in young children than adults, with 10-32% of children aged 1 to 6 exhibiting these behaviors. Pica can occur during pregnancy. In some cases, specific nutritional deficiencies, such as iron deficiency anemia and zinc deficiency, may trigger the unusual cravings. Pica may also occur in adults who crave a certain texture in their mouth.