Sorry I am confusing things probably here.
Was certainly not recommending fybogel - a distraction!
I think the trick might be to find a form of gloomy fibre (cellulose type) that gently smooths things along, and not a kind of fibrous fibre that can irritate sore gut. One is abrasive and the other is not.
As far as gut bacteria are concerned - does manuka help them? I had not heard this specifically.
2 possible ways that I know to settle gut bacteria - yoghurt bacteria (same as they have in yakult etc) but they tend to be milk based. So the purified versions may help to restore the inner ecosystem. This is just a theory as far as I know. They can help reduced the duration of infectious diarrh. and prevent but not treat antibiotic related diary.
the other way is prebiotics - that feed up your gut bacteria. these are naturally found in lots of veg foods BUT many of them may be too fibrous-fibery for your tender innards. Again you can get purified versions. And again, early days, theoretical and evidence is thin on the ground.
May be worth asking your doctor next time you are in hospital as they might prescribe, possibly.
But the priority is to find the diet that gives you the most comfort and calm!
Things you find stressful that other people don't notice.
Is there such a thing as delicious ready meals?
How do you acknowledge Easter.