I also don't want to offend pigs but I do think women, in general, are often just fobbed off with symptom control and very little actual diagnosis - which bearing in mind we can also fall victim to serious stuff like ovarian cancer with no symptoms at all, has always felt a bit silly and a false economy as you say graphista.
DDs period aren't really heavy actually. The ovulation symptoms have been quite variable (hence we've given it quite a lot of time to enable the building of a picture of whether it was going to settle down or whether it was always going to be an issue every month). It's still not the exact same replicable issues each month but it is enough to knock her off being able to go to school, and not least since if it's a day where she has sport (she's a sports student too) then she doubly doesn't feel up to it.
There's also issues like ovarian cysts which can be hugely painful and as you say, masking the symptoms isn't necessarily the right thing to do and I totally get your point.
I think for the moment something to stop the ovulation will be enough and probably sensible in view of the looming exam period, and review it again after that (because let's be honest there's risks to being on oral contraceptives).
What we would do if we were told 'it's endometriosis', I'm not sure though.
I do wonder if she needs diagnosing for an ovarian cyst though.
This is what always concerns me (with going to the GP) for anything really.
I don't go dashing to the GP as soon as there's a problem. Not least because I know the first thing they're going to say is "let's leave it a while and see if it improves" - so why go straight away, do that first, give it time. Then the next thing is "oh just try painkillers" - so again, why not try that first, see if tablets and hot water bottles is enough, don't go to the GP straight away. Maybe tack on trying other remedies (herbs, whatever) to see if they help - all to avoid burdening over burdened GPs. But then when you go and say well we've been tackling this for 1.5 years, I don't know what it is, but it seems to almost count against you! I've done the waiting, I've done the first line treatments, I've tried other treatments, none of that's worked so I'm coming to you now for the actual formalised treatment that is clearly needed - and it's almost as though because you've not repeatedly gone to the GP loads of times, you've not built up a history of the issue with them and they don't always seem to trust or be happy to give you treatment - which seems to fly in the face of what they tell us about not seeking NHS treatments unless we really need them. Sometimes feel you can't win. So part of my asking is that I always go into a GP appointment with the expectation of being buffed back out the door again! When I do actually need treatment.