I will kick-off! I did a one week fast (doctor supervised), I had abouit ~250 calories a day and some supplements. After the fast I went onto a FODMAP diet for 4 weeks and then slowly re-introduced different foods.
Result: No more IBS even after caffeine, general better feeling of wellbeing, dropped a couple of KG in the process and didn't see any decline in the following benchmarks; 5km timed run, bike FTP, back squat and bench press.