There have been few comparative studies, and the trials have been so small, that it is difficult to determine what constitutes effective treatment of constipation in the elderly. The majority of trials have been carried out in hospitals and nursing homes so there has been no adequate assessment of the effectiveness of laxatives in elderly people living in the community who are likely to be younger and more mobile. There have been few direct comparisons between different classes of laxatives and between different types of laxative within classes. The cost of treatment with laxatives varies widely. Some of the most expensive laxatives, in particular, are also becoming the most widely used, without the danthron laxatives, evidence that they are more effective. Much additional research is therefore needed to determine the most cost-effective method of treating constipation in the elderly.