Bisacodyl
"I have suffered with OIC for many years because of intractable pain and opioid medicine usage.  Its not uncommon to have to take a medicine daily such as miralax but occasionally its just not enough.  I had a few of the ducolax suppositories and felt the discomfort of three day constipation was worth the probable experience.  I have taken this medicine many times and usually the same results.  First and always DRINK PLENTY OF WATER.I CANT STRESS THIS ENOUGH.  IT WILL ONLY HELP.  Depending on how long you can hold the suppositories in... for me there is cramping within 5 minutes, uncomfortable but not horrible.  If i can continue to hold it in and only pass a little gas, from start to finish is less than an hour.  Works yes, worth it, mostly"