This article is about
IBS, but it uses the term minimal (or low-grade) inflammation to describe an increased number of inflammatory cells in the mucosa.
gut.bmj.com/content/51/suppl_1/i41.fullI'm no expert, but I'm pretty sure that even 'mild' inflammation can be seen on a scope with the naked eye. There are different degrees of visible inflammation; it starts off with redness and swelling, then if the inflammation progresses it forms ulcers. Minimal inflammation makes it sound like there's no visible inflammation that can be seen, but there are inflammatory changes at a microscopic level.
Confirm with your doc though, obviously. His idea of 'minimal' inflammation may be different to mine.