Constipation--modern laxative therapy.

It is estimated that one third of the population in Western industrial countries suffers from constipation at least from time to time. Constipation may have somatopathic or functional causes. Furthermore, a great number of substances are known to cause medication-induced constipation, i.e. opioid-induced constipation is caused by linkage of the opioid to opioid receptors in the bowel and the central nerve system. Whenever possible, causal therapy should be undertaken. Patients in palliative care mostly suffer from chronic functional constipation. The treatment consists of basic measures and the application of laxatives. According to their mode of action, they are divided into bulk-forming laxatives, osmotic laxatives, stimulant laxatives, lubricating agents and others. Bulk-forming laxatives are not recommended for use in palliative care patients, for such patients are normally not able to take in the required amount of fluids. Osmotic laxatives are divided into (magnesium) salts, saccharine, alcohols and macrogols. Lactulose is the most popular saccharine laxative. Because of its side effects (flatulence, bloating and abdominal cramping), lactulose is not a laxative of our choice; instead, we prefer to give macrogol. Orally administered, macrogol is not metabolised and pH value and bowel flora remain unchanged. Macrogol hydrates hardened stools, increases stool volume, decreases the duration of colon passage and dilates the bowel wall that then triggers the defecation reflex. Even when given for some time, the effectiveness of macrogol will not decrease. Because of its high effectiveness and commonly good tolerance, macrogol has become the laxative of first choice in palliative care patients with all kinds of chronic constipation, if these patients are able to take in the necessary amount of fluids. From the general medical point of view, lubricating agents have become obsolete. In palliative care patients, however, they are still important laxatives for prophylactic treatment or therapy of constipation. Due to clinical experience, in palliative care a laxative ladder has proven successful.