I actually found several articles that say constipation IS a side effect of peritoneal dialysis. It happens due to restrictions on your diet and fluid intake and sometimes your medications.
Have you spoken with your doctor about this? Have you discussed how much fiber you are getting in your diet? Are you eating things like whole-grain bread and plenty of fruits and vegetables?
Are you able to get any exercise? That can also help with constipation.
Please call your health care provider's office and make sure they know that you are having constipation on nearly a daily basis and are having to use a laxative this often. They may have specific recommendations for you to follow. You will not be the first patient that has had this trouble, I promise. Will you do this for us? And then come back and let us know what the doctor or nurse says?