Hi cindybt,
Thickening/inflammation of the colon is something that is fairly typical for people suffering from Crohn's Disease. Unfortunately, the amount of thickening can vary greatly between people. Some people may be able to function almost totally normally while some people may be in great pain and not able to eat anything without causing significant pain.
It is probably best to try consuming only food that is very very soft (i.e. banana, vegetables that are boiled and mashed like carrots) and making sure you chew and eat slowly. If you can not even tolerate this (or can not even drink water without significant pain) you might have want to try fasting for most of a day and seeing if that gives you any relief. I know in the past that some days by fasting (no food and practically no drink) for part of a day or a day would allow my body to rest and be able to digest soft food afterwards.
If these things are of no help, it is likely time to try going to a doctor or even hospital emergency room. If the thickening is so bad that you can not eat then there likely needs to be a change in how you are being treated. This could be through introducing a new way for your body to get nutrients/vitamins without eating (Total Parenteral Nutrition), a change in medication or even surgery.
The above are things I have gone through in the past to deal with my small intestine thickening so they may not directly relate to your case or be the best options for you.