Among patients with advanced cancer, troublesome and persistent constipation is a more common symptom than pain. The major causes of constipation in cancer patients are inactivity, treatment with opioids, and poor fluid intake and nutrition. Opioids act to both decrease gut motility, decrease intestinal secretion and therefore harden the stool. Additional aetiologies of constipation may be related to the cancer itself, general debility, concomitant diseases, or medication use. Analysis of results from one centre participating in a multicentre, prospective, longitudinal follow-up study, has confirmed the high incidenceof constipation among opioid-treated cancer patients and revealed that even optimal management of this symptom is only modestly successful in reducing constipation. This study also indicated that, in constipated cancer patients, bowel care entailed an average of 20 to 70 min per week of medical time and 55 to 120 min per week of nursing time, underscoring the high financial cost of this symptom to the health care system. Accordind to another study, which involved 50 consecutive cancer patients referred to a palliative care unit, the development of resistant constipation was independent of morphine dose. However, this study revealed a highly statistically significant correlation between resistant constipation and patient functional status, which highlights the critical and often underestimated role of immobility in the development of constipation.