Richard Herring is contemplating adding a trigger warning to his new stand-up show - because it's causing so many men to faint.

Currently performing work-in-progress dates of his upcoming Can I Have My Ball Back? tour, which is about the loss of one of his testicles to cancer, it appears that the intimate details of his operation are proving too much for squeamish audience members.

Herring has counted five men passing out so far, with two in the same night at the Bill Murray club in London on Monday.

"This is a very weird phenomenon with this show" he wrote on his Warming Up blog. "There is some light discussion of how the operation went and the after effects and four times now at the Bill Murray (and once at the Ealing gig I did) a member of the audience (always male, always testicled) has had this weirdly similar reaction.

"It's like they have been hypnotised and passed out, whilst still somehow almost awake. With eyes open they start lolling and go limp and it looks like something pretty serious is happening. I don't know if it's because the Bill Murray is a little claustrophobic so it might not happen elsewhere, but I suspect it's more to do with a sympathetic reaction to the loss of a friend. The fact it happened twice tonight was a little freaky."

Marvelling at his "great responsibility for me to have this power" and seeking a happy ending for it, Herring recalled that when a similar incident took place during his 2002 show Talking Cock, when he described a penis having its banjo string snapped and blood spurting all over the place, he was invited to the faintee's wedding.

"So hopefully all men I've poleaxed on this tour will invite me to theirs' too" he concluded, somewhat optimistically.