I think the problem is that it hasn't proven to be "effective". Have there been any placebo-controlled trials at all? Even the 'positive' trial for C dificile w

I think the problem is that it hasn't proven to be "effective". Have there been any placebo-controlled trials at all? Even the 'positive' trial for C dificile wasn't placebo-controlled. Medical history is littered with extravagant claims for new medical treatments that end up being due to the placebo effect. Bear in mind that fecal transplant will have a HUGE placebo effect, so you need to rule that out before postulating that the treatment itself has any effect.