Looking over my cup experiences, this is what I've seen:
-- I got a lot of pain from the large Lunette (46mm wide), large Meluna (45mm wide), and medium Meluna (45mm wide) I tried. They're all medium-to-wide cups and cups that are fairly stiff. The pain is/was sharp and severe enough that I just can't wear these cups.My thought is that some combination (or combinations) of length, width, and stiffness pushes out against my deep pelvic floor muscles in a way that's painful for them and/or that aggravates the endo there -- thus, the pain I get.
-- I got a middling amount of pain from the large Yuuki (47mm wide), small Diva (43mm wide) and small MCUK (43mm wide). The Yuuki is one of the widest cups but is pretty flexible; the small MCUK has a pronounced and stiff rim but is on the narrow end of medium. I could and would wear my MCUK again if it came to it though it's not the most comfortable. (The large Yuuki and small Diva were too long for me in addition to this issue, so they went bye-bye.)
-- I did/do not get this pain at all with a small Meluna (40mm wide), small Lady Cup (40mm wide), or large Lady Cup (46mm wide).
I'm just curious if anyone else has experienced this as well -- and maybe, if there are ways to get past it. I'm still looking for ways to comfortably maximize capacity to deal with my flow from hell.