Foreign body

A foreign body (FB) is any object originating outside the body of an organism. In machinery, it can mean any unwanted intruding object.

Most references to foreign bodies involve propulsion through natural orifices into hollow organs.

Foreign bodies can be inert or irritating. If they irritate they will cause inflammation and scarring. They can bring infection into the body or acquire infectious agents and protect them from the body's immune defenses. They can obstruct passageways either by their size or by the scarring they cause. Some can be toxic or generate toxic chemicals from reactions with chemicals produced by the body, as is the case with many examples of ingested metal objects.

With sufficient force (as in firing of bullets), a foreign body can become lodged into nearly any tissue.

One of the most common locations for a foreign body is the alimentary tract.

It is possible for foreign bodies to enter the tract from the mouth or rectum.

Both children and adults experience problems caused by foreign objects becoming lodged within their bodies. Young children, in particular, are naturally curious and may intentionally put shiny objects, such as coins or button batteries, into their mouths. They also like to insert objects into their ear canals and nostrils. The severity of a foreign body can range from unconcerning to a life-threatening emergency. For example, a coin causes local pressure on the tissue but generally is not a medical emergency to remove. A button battery, which can be a very similar size to a coin, generates hydroxide ions at the anode and causes a chemical burn in two hours. An ingested button battery that is stuck in the esophagus is a medical emergency. In 2009, Avolio Luigi and Martucciello Giuseppe showed that although ingested nonmagnetic foreign bodies are likely to be passed spontaneously without consequence, ingested magnets (magnetic toys) may attract each other through children's intestinal walls and cause severe damage, such as pressure necrosis, perforation, intestinal fistulas, volvulus, and obstruction.

Sometimes foreign bodies can pass spontaneously through the gastrointestinal tract and perforate or penetrate the wall of stomach and duodenum and migrate into the pancreas. The laparoscopic approach before open surgery could be performed safely for the removal of foreign bodies embedded in the pancreas.