Hi,
Like you I'm a lifer with this problem. My IBS was caused from a serious bout of Campylobacter which almost killed me and shut down my kidneys for 18 hours leaving me with Autonomic polyneuropathy (ANS) and damaged kidneys. ANS causes the slow digestion triggering SIBO from time to time. More often now and becoming a regular occurance. I'm not sure what I would call the taste other than nasty, but palatable out of necessity! The kidneys only ever rebounded to 43% function but are reasonably stable. My diet is crap as I'm juggling T2, IBS, SIBO, BP, high Cholesterol levels and CKD dietary requirements. I live a life of constant hunger, able to maintain this state as the effect of eating gets to be a worse problem to deal with. After living on mainly bread and water for 18 months I surprised I can still summons the energy to walk 10Km when required. Knowing I now have ANS the last resort of fecal transfer would appear to be a waste of time as the ANS controls the digestive system regardless of what we have done medically. ANS has no cure or treatment so that leaves the hope life isn't going to take too long to evaporate for me. Meantime I just deal with whatever happens each day I wake. All the specialists that thought they were going to make a difference for me have found they can't, so I'm left pretty much on my own to battle on with whatever meds I might require and manage my situation as best I can.
Cheers