Gloria,
For me to say that you've asked a very good question, would probably be the understatement of the decade.

I wish I knew the answer.
Seriously, anything that I say here will have to be considered as sheer speculation, since my original statement, (that you quoted), was based on the
lack of evidence to the contrary, (rather than on facts).
Gloria wrote:Is there a difference between intestinal damage and intestinal inflammation? If so, must one continue to avoid irritants while the intestines are inflamed? Technically, my intestines shouldn't be inflamed because I'm on a maintenance dosage of Entocort, right?
Yes, there is definitely a difference. Damage refers to physical changes inflicted upon the otherwise normal architecture of the epithelia of the intestines, such as flattening of the villi in the small intestine, and any other visible, (under a microscope), changes to the surface, (or subsurface), features of the of the epithelia, (such as the thickening of collagen bands). Inflammation, (in the case of MC), refers to the infiltration of lymphocytes between the cells of the epithelia , (by definition).
Remember that the rest of this is just my opinion, but IMO, the inflammation is clearly the reason why the gut is sensitized, and the cause of most of the symptoms. The damage obviously causes malabsorption problems, and indirectly, it also causes poor digestion, (in the sense that it contributes to the loss of enzyme production in the brush border regions), but I doubt that it causes D, per se. There are a lot of asymptomatic celiacs out there who verify that point, I believe. Their small intestines show serious damage, but without any inflammation, they do not present with D.
On the other hand, most of us show minimal intestinal damage, (possibly none, in some cases), and yet D is prevalent, because of the inflammation that is a prerequisite for a diagnosis of MC, (lymphocytic infiltration). In the case of CC, lymphocytic infiltration is not necessarily a prerequisite, but it is always present, to some degree, (significantly more than normal levels, at any rate).
Therefore, since inflammation is the primary cause of D, (in the case of MC), all irritating foods, (whether they are allergens or not), must be avoided as long as the intestines are inflamed. I have no idea which comes first, the reconstruction of damage, or the cessation of inflammation, but I have a hunch they are probably linked for most of us, (though probably not for all of us), since as long as inflammation persists, the potential for additional damage clearly exists. Remember that only a percentage of the intestinal surfaces are actually inflamed, (in patches), in most cases, but normal BMs can only resume after all of those areas of inflammation are resolved.
Regardless of the Entocort, and the amount of time following the diet, you wouldn't have D, unless you still have some inflammation,
unless something other than MC is causing the D, of course, (such as parasites or a bacterial, or even a viral, infection). Also, since Entocort EC is designed to activate in the ilium and the proximal colon, it's theoretically possible, I suppose, that it might not be adequately controlling all the inflammation in the distal colon, for a severe case, such as yours. Evidence of that might be demonstrated by the fact that a higher dose might completely control the inflammation. IOW, I suspect that budesonide is not necessarily "systemic" within the colon itself, which would imply that minimal doses would be absorbed before reaching the distal end of the colon, thus leaving the distal end untreated.
Anyway, that's my interpretation, FWIW.
Tex