Trish, I've only just found the coccyx.org website today (wow!), and came across your story. My story is a bit different, but perhaps gives a different angle which nevertheless leads to the conclusion that gynae/bowel problems and coccydinia may well have an impact on each other. I wouldn't like to say in my case which is cause and which is effect, but I'm sure that problems in one will cause, or give a propensity to, problems in the other. (Not surprising I guess, considering how closely linked the musculature and ligaments are). I hurt my coccyx by a fall onto a large post on the ground when I was 10 years old - was blue from buttocks to knees, and couldn't sit down for around 18 months (had to go through 6th and 7th grade standing up!). The discomfort decreased over the following years such that I had essentially no pain for 30 years, except on odd occasions if I sat down awkwardly on a hard surface. I've kept the chiropractic profession well employed for that 30 years for various problems as a result of general joint hypermobility.
However, a couple of years ago (age 42), coccyx pain started to be a problem on long train journeys (British Rail seats are very hard on tails). At the same time, I was developing what I thought was IBS, but ultimately turned out to be diverticular disease, aggravated by a large pedunculated fibroid which blocked/put pressure on the large bowel on the left hand side - it was difficult for me to distinguish between the pain in the bowel, sacroiliac and coccyx pain, all of which was on the left hand side. In December 2004, I had a laparoscopically assisted vaginal hysterectomy - however, the surgeon commented immediately after the surgery that it had been 'technically challenging' and 'a bit of a tug', and that I might prolapse. Within a couple of weeks (as soon as I could feel anything), I had the feeling of a ping-pong ball just inside the vagina - not painful, but an irritating feeling of a lump. After a couple of months, the pain in the left side recurred - ultrasound revealed that the left ovary was hugely enlarged with fluid - this was blood, probably as a result of damage to the ovary blood vessels during the hysterectomy and I then had a left-hand oophorectomy (right hand ovary retained).
Over the next six months, I recovered from the surgery, but gradually the ping-pong lump became uncomfortable, particularly on bending, coughing, walking roughly down stairs - any action that increased pressure within the abdomen. I was told that although not 'officially' a prolapse, the anterior vaginal wall was floppy and collapsed downwards. Attempting to hold my insides up by pelvic floor exercises was unsuccessful, partly because the anterior wall was unresponsive, but also because this caused coccyx pain. I then developed extreme bladder pain, and had some difficulty emptying the bladder - it was decided that this was due to neuropraxia, and possible erroneous reinnervation/ pain signals from the bladder and anterior wall. A further factor is that, over the summer, I had the feeling that the remaining ovary has ceased to work - tests for FSH, LH, and oestrogen confirmed this. I was given amitriptyline to control the pain, and local oestrogen - blessed relief, even if some bladder pain remains, I can live with it. What is interesting is that, in the last month, my LH and FSH levels plummeted and oestrogen levels increased - it appears that my ovary, after six months of not functioning, is active again.
So what questions does this leave? I've the classic coccydinia of extreme pain on standing up after sitting. From the point of view of your question about prolapse - when I've been sitting and the coccyx is hurting badly, I can't hold the pelvic floor (or other muscles internal and perineal) and the anterior wall collapse is much worse. Pelvic floor exercises cause coccyx pain, but at the same time, if I can bear to do it before standing up, the prolapse feeling is less. I haven't had children, but a urogynae specialist I've seen since commented that the route of surgery was inappropriate for a badly fibroid uterus, and effectively was a difficult birth of a large baby, hence the trauma to the anterior wall, bladder and general pelvis area. What's more, I was not aware that oestrogen has a significant effect on bladder and indeed on other connective tissue- something else for you to think about as you seem to be a similar age.
I know that keeping my bowel as empty as possible minimizes the coccyx/ rectal type pain you describe, and also decreases the intensity of prolapse feeling - I eat porridge (Scottish influence!) every day, with added psyllium husk, and loads of vegetables and 3 litres of water daily to avoid any straining at all (with a cystocele, the last thing I need is a rectocele too). Pain symptoms from diverticular disease have pretty much gone as a result of removing the fibroid which occlude/had become parasitic on the bowel.
I also have hypermobile joints (my shoulders can dislocate if I sleep on my side or change gear roughly!), and as hypermobility is associated with a different type of collagen, and predisposes to prolapse, that's another risk factor. Because of this, and my experience with surgery complications to date, I would not contemplate surgery for either coccydinia or the prolapse I have at present. I'm hoping that reinnervation and physio will allow me to regain painless bladder function and anterior wall control - though it'll be a matter of years.
In my mind, there's no doubt about a link between coccydinia and prolapse - what role the oestrogen and hypermobility of joints play, if any, I don't know. I don't want to put you off surgery - but beware if you have hypermobile joints, and all surgery can cause neuropathic pain - short or long term. It sounds as though you have no option but to have the prolapse fixed - but have you considered pessaries or other conservative measures first? I hope some of the above might help you post-surgery. I'd be fascinated to hear your obs/gynae specialist's views.