On The Buses, Series 1, Episode 4, Bus Drivers Stomach.

Stan's stomach pains are 'an occupational hazard' from sitting over a vibrating engine all day according to him, but Arthur has other ideas. Further details When Stan is troubled by stomach pains he insists it is an age-old complaint amongst bus drivers called 'Bus Drivers' Stomach', caused by sitting over the rumbling bus engine day-in, day-out. Arthur's less than convinced and blames his pains on a diet of chips; when he quotes some alarming facts from a book concerning eating habits, Stan is put on a diet. To make matters worse the management are seeking to remove all unfit drivers from their posts so it is imperative Stan passes the planned medical. Can he stick to the diet or will the call of the fryer win?