Lactulose

Lactulose is a non-absorbable sugar used in the treatment of constipation and of hepatic encephalopathy. It is taken by mouth for constipation, and either by mouth or rectally for hepatic encephalopathy. It generally begins working after 8 to 12 hours but may take up to 2 days to improve constipation, and it is classified as an osmotic laxative. Common side effects are abdominal bloating and cramps, and because it produces diarrhea there is a potential for electrolyte problems. No evidence of harm to the fetus has been found when it is used in pregnancy, and it is generally regarded as safe during breastfeeding. It was first made in 1929 from the milk sugar lactose, which is composed of galactose and glucose, and has been used medically since the 1950s. It is on the World Health Organization List of Essential Medicines and is available as a generic medication.