'Sorry to hear things are so rough :( Here's a checklist:
--Be sure that you're not eating or doing things you know can make you worse.
--Are you making sure you're having adequate bowel activity (IF#1 or enemas = 3 bms daily) Honestly, it sounds to me like it's very possible you're stirring up a lot of junk in your colon and you may be having 'nerve pressure' from this (and getting ready to get rid of some of the problem). So hit the foot reflexology HARD wherever you're feeling pain, and particularly on the colon & sciatic nerve points. Stay hydrated!