I would second JAB regarding MMS. I believe that prolonged and/or heavy use can result in a heavy toll due to the oxidative stress that MMS causes.
Colloidal silver, especially when combined with plant derived trace minerals, can be very effective against Crohn's as well as Candida. You will need something else for parasites, but there are lots of options besides MMS. Perhaps you may find some helpful suggestions here:
Keeping your colon and intestines cleansed and taking plenty of vitamin C, digestive enzymes (such as Garden of Life's Omega-Zymes which is my personal favorite) and cayenne will likely help soften and heal your lower intestine. I rather imagine that Dr. Christopher's Complete Bone, Skin and Tissue capsules may contain healing items that will help as well.