Good evening @daan! Following through, as promised, what started out as a reply here turned into a post:
Survival Tale: My Battle with Intestinal Infection
Reliving it brought mixed emotions, but overall I am happy to have gotten it down. It may help you and, hopefully, some others along the way.
While I do not know specifically if what ails you is anything like what I experienced, I am confident what I learned about the essential importance of our intestinal health will be of some benefit to you.
Until we "meet" again, I hope you are at least feeling some better!