An increasing number of small boys seem to be affected
An increasing number of small boys may be finding toilet training a more painful experience than they anticipated, say safety experts.
Doctors at one English hospital reported four cases in which a toddler's penis had been injured by a falling toilet seat.
The fashion for heavy wooden and ceramic seats is worsening the problem, they say.
Figures suggest there may be up to 250 similar cases a year in the UK.
Dr Joe Philip, from Leighton Hospital in Crewe, said that parents might need to take more precautions to keep their young sons out of A&E.
He called for more seats to be designed to fall slowly, and for heavier seats to be banned from households with young boys.
He even suggested that the social norm of putting the seat down after use be suspended and the seat fixed in an upright position.
He said: "As Christmas approaches many families will be visiting relatives and friends and their recently toilet-trained toddlers will be keen to show how grown up they are by going to the toilet on their own.
"It is important that parents check out the toilet seats in advance, not to mention those in their own homes, and they should accompany their children if necessary."
The four boys visiting the Crewe hospital, aged between two and four, all needed to stay in hospital overnight, although fortunately no lasting damage was done.
They had all lifted the toilet seats themselves, which had then fallen back down onto their penises, the journal BJU International reported.
Dr Philip said: "A recent market research report has suggested that there has been a worldwide increase in the number of wooden and ceramic toilet seats sold.
"We would not be surprised to hear that other colleagues have noticed an increase in penis crush injuries as a result of this."
He said that parents should consider training their youngsters to hold up the toilet seat with one hand.
A spokeswoman for RoSPA confirmed that the cases at Crewe were not isolated examples.
Sheila Merrill, home safety manager for England, said: "The most recent figures show there are an estimated 250 visits to A&E each year by boys under the age of five involved in similar accidents.
"So perhaps it's advisable that parents with toddlers think twice about having heavy toilet seats while their children are young.
"However, as with children of all ages, in all areas of the home, supervision is always the most crucial aspect in preventing accidents."