Foreign Bodies can be useful sometimes. Recently had a child that had inserted a penny up their nostril (they did'nt trust the bank) . During examination I asked the child how old they are. They said "+" years old, Dad said "-", a good 3 years younger. After a bit of investigation (and realising that the child had a better vocabulary than I do and would have been considered gigantic for a "-" year old) the child did indeed turn out to be "+". Dad was on the run from a city in the north and had taken his child with him, child was "known" to other agencies. Thing's up arses' are fairly rare occurences though I think. I only ever saw 2. First was a Lynx deodorant can (with cap) and the other was a corgette. Both patients were male and very embarrased. The X-rays are always something else entirely!