Fasting is a simple thing whereas, IBS is very complex. Dr Walker determined that the one guy's only hope was carrot juice only for one year since his colon was messed up. The holes in the colon are only when the person has leaky gut also. That is what dragons blood is best for-- leaky gut syndome. Things are so complex with IBS, that one of the healthiest things in the world, like raw vegetables, can create problems like with the person above.
Another thing good for healing the colon is chlorophyll which is what makes greens, like spinach, green. There are greens drinks that have a lot of chlorophyll but also have over 10 different probiotics which are also great for IBS. See this site for more on Greens Drinks. Also in health food stores, they sell rotten tea with moldy fungus. This is very good for IBS. It is a bacteria called "kombucha tea."