Lactulose AIWA 670 mg/ml oral solution pharmacy-only active ingredient: lactulose Lactulose AIWA contains a laxative called lactulose. It makes the stool softer and easier to pass, by drawing water into the bowel. It is not absorbed into your body. Lactulose AIWA is used to: • treat the symptoms of constipation. • treat a special liver disease (portal systemic encephalopathy). Packs of 200 ml, 500 ml and 1000 ml are available.