I will answer to myself as I find a scientific article which, probably, clears me the question. It's "Endoscopic and histologic evaluation together with symptom assessment are required to diagnose pouchitis" https://www.gastrojournal.org/article/S0016-5085(01)18749-4/fulltext in which can be read: "Eight of 22 patients (36%) had only mild symptoms with symptom scores of 2, which would not typically suggest the diagnosis of pouchitis.However, these patients had high endoscopic and/or histologic scores and achieved a total PDAI score of 7 or higher.For these 8 patients, the mean total PDAI score was 9.2 ± 2.2, the mean symptom score was 2.0 ± 0, the mean endoscopy score was 3.9 ± 1.2, and the mean histology score was 3.3 ± 1.3.All 8 patients were treated with a 2-week course of metronidazole or ciprofloxacin and responded with a reduction in the total PDAI of 3 points or more.The mean posttreatment PDAI score was 4.0 ± 1.5, symptom score was 0.6 ± 0.8, endoscopy score was 1.1 ± 0.9, and histology score was 2.3 ± 0.5.The mean reductions of the PDAI, symptom, endoscopy, and histology scores were 5.1 ± 1.8, 1.4 ± 0, 2.6 ± 0.8, and 1.0 ± 0.8, respectively, all of which were significantly lower than the pretreatment scores (P < 0.02 for all comparisons)."
This seems to answer me. I respond to antibiotics, and even when I've got pouchitis I have a very good quality of life which I represent as: "can work, can go out, can eat what I want" and so. And after the course of antibiotics, usually I'm even better. Nevertheless I've got really endoscopic and probably histologic scores... This is like I'm feeling not alone with this and in my ignorance I couldn't find the fact that endoscopy could be really bad but, you can have just a mild pouchitis...