I actually managed to get an appointment with the doc yesterday! (It is a big thing because on average the waiting list at my local clinic is 10-14days, but I said it was an emergency.) She prescribed me some Movicol and Rectogesic, so hopefully they will help with the pain.
I read the leaflets etc, so I know that the rectogesic can cause headaches, and took the first dose last night. Immediately I got a headache. I wasn't sure whether it was really related (or just because I had just read to expect a headache itms) so drank even more water, but didn't take any pain killers. That headache developed overnight into a migraine. :-( I have since dosed up on ibuprofen, and the headache seems finally under control, so I took a second dose of the rectogesic this morning. Whilst it is better than before, I can still feel the headache lurking in the background.
I want the ointment to work, so am tempted to put up with the headaches and just keep dosed up with the painkillers. But, I'm not really meant to take ibuprofen as I'm asthmatic (though I've never had a reaction, so far) and find paracetomol just isn't strong enough for migraines. Or should I go back to the GP anyway?
Obviously, if the migraines become constant (rather than just whilst my body gets used to the medication) I will be forced to go back to the doc anyway.

I've just had my first BM since this new medicine, and i can't believe it. Slight discomfort, but no razor-blade pain and no blood. I'm in shock - I'd forgotten what this feels like! :D
BUT, I took some more rectogesic and again within 10mins i've a throbbing headache. I've taken some nurofen straight away, so hopefully I'll avoid another migraine, but it puts me in a quandry, as I don't want to have these headaches everyday.

Bernie-
Rectogesic is Nitro paste. It is a vasodilator so it is dilating your blood vessels throughout the body including the head, hence the headache.
How are you applying it? You want to minimize contact with skin as much as possible. So use a finger cot or even a Q-tip to apply to minimize getting it on your finsgers. You could also experiment with the amount applied with the goal of applying only as much needed to relax the sphincter muscle.
I have also read that nifedipine in a topical form doesn't cause the headaches like nitro does. Not sure what it is called in the UK.
I tried nitro paste several years ago. I had headaches but they got better with time. When I tried nitro later ( a 2nd round) I developed a cardiac reaction - heart racing. I assume this is because it made my blood pressure drop to low.
Good luck.

Sorry that you are getting headaches, Bernie. Nitro seems to do that. I think Paulspains advice is good.
I am on Nifedipine and it had no reaction on how I feel in my body. No headache, and no heart racing etc. Have yet to see if it has any results on where it is meant to work...
The reason CRSs in the States seem to prescribe Diltiazem and Nifedipine (both calcium channel blockers and used to control blood pressure) if because of the adverse reactions so many have to the nitro. My surgeon did not even suggest it.
Good luck to you!
Em