Consider osmotic laxatives if others do not work
Typically, osmotic laxatives will be recommended to a person with ulcerative colitis only after bulk-forming laxatives have failed to resolve the problem. Similar to bulk-forming laxatives, these agents work by increasing the amount of water along the gastrointestinal tract, specifically in the intestines, inducing bowel movements and making them easier by softening stools.
Some people prefer osmotic laxatives to bulk-forming laxatives because there is a lower risk of developing side effects, and the laxative is slow-acting. It typically takes between two and three days for a bowel movement to occur after the laxative has been taken. Since bulk-forming laxatives tend to be the first course of action in treating constipation, it is recommended that osmotic laxatives be used after bulk-forming laxatives have been attempted.