The bowel habit of 350 preschool children from a single general practice was studied. Eighty five per cent of 1 to 4 year olds eating a predominantly low fibre diet opened their bowels once or twice a day and 96% of the children fell within the range of three times a day to every other day. At all ages most children produced soft stools of about 25 ml volume. Mean intestinal transit time of 35 (10%) randomly selected children was 33 hours. There is a significant correlation between infrequency of bowel action, longer transit time, hard stools, and the passage of blood.