The cause of my disease also causes chronic GI issues, and constipation/regularity is part of it. I take double doses of
Miralax on some days, a normal
dosage on the others. My doctors have no problems with it. Other laxitives should be ok'ed by your doctor though. But I am like you, BM's are a rarity most times, but the Miralax helps a great deal.
Btw, my primary disease causes severe bile issues. Small world, take care!