'Boil it, cook it, peel it or forget it': does this rule prevent travellers' diarrhoea?

A total of 688 out of 2240 air charter passengers in flight to Kenya, West Africa or Sri Lanka/Maldives volunteered to participate in a follow-up study investigating the influence of various food and beverage items on the incidence of travellers' diarrhoea. Within the first three days of their stay abroad, 98% accepted food or beverages whose avoidance is traditionally recommended. The incidence of diarrhoea, which was 19.5%, was proportionate to the number of dietary mistakes committed. The most dangerous items were those whose avoidance was traditionally recommended.