How long does it take to have a bowel movement after drinking Lactulose Oral Liquid varies from person to person, some people may have a bowel movement in 3~5 hours, while some may have a bowel movement after 12 hours. Oral lactulose oral solution reaches the colon, increase the osmotic pressure of the colon, stimulate intestinal peristalsis faster, but also increase the water in the feces, is conducive to fecal discharge; constipation time is relatively short, the condition is not serious patients, taking lactulose oral solution after about 3 to 12 hours can be defecated. If the constipation time is longer, the time of defecation after taking the drug is relatively longer. Lactulose Oral Liquid may cause the adverse reactions of abdominal distension, abdominal pain and diarrhea. It should be used with caution in pregnant and lactating women, and is contraindicated in cases of intestinal obstruction and acute abdominal pain. It is recommended to use this drug under the supervision of a physician, do not take the drug on your own.