A postal questionnaire about knowledge, beliefs, and experiences of bowel function was returned by 171 patients aged 55 years and over from a group general practice in London. Of the respondents, 10% reported no predictable frequency of movement, a higher proportion being women than men; 79% believed that a daily movement is important and 90% that ‘regularity’ is necessary for good health; 14% were dissatisfied with their bowel habits and 16% regularly self-treated; 95% gave reasonable definitions of ‘regular’ and ‘diarrhoea’; a tenth were unsure about the definition of ‘constipation’. Although 76% believed there were bowel symptoms which require immediate medical attention, 98% would in the first instance treat themselves for constipation, 90% for diarrhoea, and 25% for rectal bleeding. To reduce delay in the diagnosis of colorectal cancer, it is suggested that consultations for disturbance of bowel function be encouraged among the middle-aged and the elderly. Doctors should examine such patients with the diagnosis of malignancy in mind.