Laxative abuse is an unusual but probably under-recognized cause of chronic diarrhoea. We describe two patients diagnosed to have this condition in our unit over a five-year period. The typical patient is a female presenting with severe, large-volume, watery diarrhoea. There may also be abdominal pain, weight loss, nausea, vomiting and hypokalemia. By the time of diagnosis most patients would have seen several physicians, been hospitalised on one or more occasions, and some would even have undergone operations for their conditions. A high index of suspicion is required to make the correct diagnosis. Unnecessary and repeated investigations can then be avoided, even though treatment may not be satisfactory.