Laidlomycin Hydrochloride Hydrate Products | Cleanchem - Lactulose is a synthetic sugar used primarily to treat constipation and hepatic encephalopathy. In the colon, it is broken down by bacteria into acids that draw water into the bowel and lower the pH, trapping ammonia and reducing its absorption. This makes it especially useful in patients with liver disease to reduce blood ammonia levels. It is taken orally and is well tolerated with minor gastrointestinal side effects.