Ex lax is a senna derivative used to treat constipation and empties bowel for an operation. This drug is a laxative which take 6 - 12 hours to work. Ex lax is taken 1 hour before meal or before bedtime.
Ex Lax will take a few hours to work. It may take overnight depending on the severity of the constipation. Many people seek relief from Ex Lax at some point or another. This is a mild medication that helps the bowels move.