Celiac disease often has no or few symptoms, and the only reason it's caught it through blood test and subsequent endoscopy. It does cause damage even if it isn't causing symptoms, so I wouldn't leave it.
Though an endoscopy sounds like an extreme step, it's a fairly routine test. Siblings of children diagnosed with celiac disease are often screened for celiac with an endoscopy, even if they don't show symptoms AND have a normal blood test. If it were me, I'd do it.