The laxatives that were prescribed to me in the hospital did absolutely nothing. By the 3rd day after surgery I stopped eating. I asked for Magnesium Citrate. I think I drank the whole bottle. Worked wonders.
I recall the nurses in the hospital used a combination of 3 laxatives to control the stool. They certainly wanted to avoid the constipation, and, if anything, be on the softer side. (And this was the only type of medications that nurses could dial.)
Was also sent home with two of these laxatives, for the same reason. Only remember one -- senna (OTC).
Would highly recommend the pre-surgery consumption of carbo-hydrate drink, as directed. It helps restart the stomach after the surgery.
Believe the walking also helps -- as if you didn't have enough reasons for doing it )