Stimulants—Stimulant laxatives, also known as contact laxatives, encourage bowel movements by acting on the intestinal wall. They increase the muscle contractions that move along the stool mass.

How long does an oral laxative take to work?

Bulk-forming laxatives can have some effect within 12-24 hours but their full effect usually takes 2-3 days to develop. Osmotic laxatives such as lactulose can take 2-3 days to have any effect so they are not suitable for the rapid relief of constipation. Stimulant laxatives usually work within 6-12 hours.

How long does oral Dulcolax take to work?

It may take 6 to 12 hours before this medication causes a bowel movement. Tell your doctor if your condition persists or worsens, or if bleeding from the rectum occurs. If you think you may have a serious medical problem, seek immediate medical attention.