Thanks, Rian. I read that explanation when I was researching, and it might hold true, but in my case the pain vanished within 24 hours of eating. Given that, the āfast abdominal fat-lossā issue doesnāt make sense. My fat loss held, within 24 hours of breaking the fast, but the pain evaporated.
I read in Valter Longoās book, in a discussion about the pros and cons of Prolon, his fasting mimetic, that one con could be ālower back painā. I messaged his FB page asking what would cause such pain but didnāt get an answer.
Iām thinking of going to True North Iām March to do a true extended fast. Itās clear to me now that without extreme circumstance (straight jacket, desert island, āfasting facility) Iām not likely to fast for a long period. And while the short fast helped my inexplicable belly distention, it didnāt fix my constipation, which is my #1 reason for fasting.
True North aligns with the vegan religion, so could be bumpy on the refeed. But then again, my high fat/low carb lifestyle was in full swing when my health went whacko, so 3 days of fruit and veg refeed might be a good change of pace. I wonder how Iāll look at fruit after a long fast? Probably love it versus my current DANGER view 
Let me know how your back did with the golf swing and breaking the fast. Thanks again for sharing your info.