So the answer to the responses I received is yes, what you're experiencing is normal. Secondarily, how frequently you pass a mucus plug depends on too many factors to give you a useful number.
How frequently one passes rectal mucus depends on many things.
The inner lining of the intestines is one of the most often renewed surfaces in the human body, replenishing itself every 2 to 4 weeks. (1 MILLIMETER THICK!)
It also depends on:
How much bacteria was in the original stump.
Whether your stump still has active ulcerative colitis or Crohn's disease.
How many vitamins C, E, and folate are in your diet.
Whether you are still an active smoker and
possibly other factors that have not yet been determined.