I got a theory now, that it could be an Antibiotic tablet that was stuck in a diverticul. Then it would be unreachable by any bacteria that comes close to it to break it down because it kills any bacteria in the perimeter.
Is it possible that an Antibiotic tablet can survive 18-20 years in the intestines while permanently releasing the active antibiotic? I guess they're also enteric coated. Could it be the reason why we got so much yeast overgrowth? Maybe these slowly dissolving tablets are the orange or yellow seeds that so many people see in their stool (now that they use DE and enzymes)?
I got Antibiotics once for a pneumonia and once for a hole in the eardrum.