I'm so sorry to hear that you are feeling so badly. I just posted a message regarding constipation...read it and see if any applies to you.
When you say 'mucous and pus', can you describe what it looks like? Is there ever any blood present? Do you ever have bouts of diarrhea? Does it contain a lot of mucous, pus or blood?
What have you already done to address the constipation?
I'll try to help you...having some more information will help me.