Recent life change and large bowel cancer. Data from the Melbourne Colorectal Cancer Study. In a large, population based, epidemiological study of colorectal cancer, The Melbourne Colorectal Cancer Study, several etiological factors were investigated. Persons' recent life changes, as well as the degree of upset they experienced as a result of these changes, were included. Interviews with 715 histologically confirmed new cases of colorectal cancer occurring over a 12-month period in Melbourne, Australia, and with 727 age and sex matched community controls were conducted. As one of the methods of assessing any effect of recall bias, 179 hospital controls were also investigated. Major illness or death of a family member, major family problems and major work problems were found to be significantly more common for cases over the 5 years preceding diagnosis compared to controls. Cases also reported being significantly more upset with their recent life changes than did controls. No significant differences in results were found between males and females, or between colon cancer and rectal cancer patients. Although the possibility of recall bias, was not completely controlled for in this study, it was probably not an important factor in explaining case-control differences. Recent life changes, and their perceptions, may have significance in the development of large bowel cancer. 