>>>Could I be correct in saying those are "shot gun" guesses and no one know how to prevent the disease.
Quote:
"There is currently no clinical evidence to fully prove the link between fibre and diverticula. However, diverticular disease and diverticulitis are both much more common in Western countries, where many people do not eat enough fibre".
Source:
http://www.nhs.uk/Conditions/Diverticular-disease-and-diverticulitis/Pages/Causes.aspx
So we're in a similar position to what we used to know about the link between smoking and cancer. (i.e, there was a time when nobody had
proved that such a link existed but it was blatantly obvious that one actually did).
Interestingly, the NHS website concentrates almost solely on a lack of fibre and makes no reference to the other factors suggested in your post:
http://www.nhs.uk/Conditions/Diverticular-disease-and-diverticulitis/Pages/Prevention.aspx