I'm sceptical of this for crohn's disease. The bacterial load is much higher in the colon than in the small intestine. While there is dysbiosis in crohn's disease, an unbalance or shift in bacterial population, this happens in many many intestinal diseases. If you believe in FT you believe the dysbiosis is behind the inflammation, while in every other disease so far, dysbiosis is a result of intestinal inflammation and is not the cause behind the inflammation. There is dysbiosis in intestinal tuberculosis of the small intestine, but people would call you crazy if you treated intestinal tuberculosis with a fecal transplant. Then there's the fact NOD2 / ATG16L1 / IRGM are involved in intracellular control of pathogens, not gut flora, there's the fact CD8+ T cells are involved in crohn's disease, which are cytotoxic to cells, not gut flora. There's the fact inflammation in crohn's disease is transmural. There's the fact inflammation in crohn's disease is patchy.
There is a whole laundry list of reasons why I"m very sceptical about FT. FT is I feel also wrongly portrayed in the media...."you just add good bugs"...when you take probiotics or when people do a fecal transplant, massive amounts of cytokine and inflammatory protein can be measured in the bloodstream, thousands of those bacteria die off and a whole chain reaction of events happens. It is not as simple or wonderful as the media portrays. Many probiotic strains have warning labels that they should never be used on an immunocompromised person.
If you give a FT to treat crohn's disease you are making a leap of faith. The faith that dysbiosis is behind the inflammation..no one knows..many people argue it's not, and the faith that whatever you're giving this person (only a small percentage of the gut flora is known so far)...is actually going to help that person and not make the dissease worse. It's a leap of faith I as a crohn's disease person refuse to make, I do not think there is enough data or reason to believe this is without risks.