1 MARCH 1986, Page 23

Bowel gas

Sir: Ludovic Kennedy's pleasure in his 'colonoscopy' ('A voyage round my colon', 15 February) would have been diminished, I fear, had he taken the trouble to read up something of the history of this operation. The heat with which his polyps were cauterised is generated by an electric arc. Given the combustible nature of the sur- rounding atmosphere it is not difficult (in retrospect, at any rate) to see how 'death by fatal bowel gas explosion' came to appear on a number of American death certificates in the 1970s. The snag appears to have been overcome: perhaps there are advantages in being just a little out of date where medical technology is concerned.

Jonathan Pressey

The Well Cottage, Newnham Green, Hampshire