I'm young just like you (22 y/o) and understand how devastating something like this can be to your life. The poking and prodding is rough, but honestly, you just have to get used to it, because with a chronic disease needles are quite common.
I was also going to say that Pentasa really isn't going to be causing you any of those problems, it will be your disease. Best thing to do is to attack your health problems from the core.
Don't worry about the colonoscopy! It's plenty easy, no pain and from start to finish it is very quick!
Also, I definitely agree on the steroids!
As for the thyroid issues, do not fret over that. It may be a pain now, but once you and your doctors are able to find the right medication for your thyroid issues, you will feel LOTS better. Chances are, the underactive thyroid is what is making you feel really crappy. As soon as you are able to take care of it, you will feel loads better!
Lastly, I would always talk to your doctor before trying new things.
We're all here for you for whatever you need!
Sarah, 22 y/o.
Several Bone fractures due to Prednisone
Thyroid Cancer, Severe Crohn's Disease- perianal, many more...
Current rx: Celexa, Lomotil, Pentasa, Humira, Klonopin, Prednisone, Synthroid, Zinc, Multivitamin, Calcium w/ Vitamin D, Fentanyl, Ambien, Depo Provera, Align, Zofran, Lansoprazole, Propranolol, Dilaudid
Past rx: Remicade, 6MP, Flagyl, Cipro, Entocort....