Management of constipation in patients with cancer.

Constipation is highly prevalent in patients with cancer and is a source of tremendous suffering. The physiology of the gastrointestinal tract and the pathophysiology of constipation are being elucidated. Therapeutic agents include stool softeners, osmotic agents, stimulant laxatives, lubricants, and enemas. Synergism of these agents, which act through different mechanisms, is often required to successfully treat constipation. Selective serotonin agonists and peripherally acting opioid antagonists are being studied and may prove to be important additions to our pharmacologic armamentarium.