Hello there!
Thanks everyone for sharing your thoughts and experiences!
Actually, the examination last week went really well. To begin with, they wanted to give me just the sedatives they gave me last time (when the whole thing had to be called off). I protested and tried to explain my pain in the most colorful language I could muster. It worked and I actually don't remember the examination after they had given me a couple of injections. I woke up outside the examination room, quite relieved and happy the whole thing had gone so well!
On the bad side, the doctor told me they hadn't and actually can't see fissures with endoscopy (you were right there, NGuy!). However, they did see some pus. So now they worry there might be an abscess. They gave me antibiotics and said I will be called to an MRI as soon as possible. Also, they will make an examination under narcosis, where they inflate the intestine in order to better see fissures and fistulas (I really hope I haven't got one of those! ).
Anyway, the last week I have really felt some improvement 'down there'. One of the days I actually woke up and didn't feel anything strange from the rectum - no pain, no itching, no strange pressure. It was very encouraging! So now I'm arguing with myself whether this is because of the antibiotics or because of the new tablets my homeopath gave me last week. I am sort of hoping it's the homeopathic remedies, because I wouldn't really like to find out I have an abscess. And it would be cool to be convinced about the effects of homeopathy (I'm an open sceptic). On the other hand, perhaps the fissure is starting to heal on its own!
Well, today it started to bleed from what I think is the fissure. I am not scared by blood on the toilet paper - it's quite common in an IBS patients life. But now I'm nervous about a retearing of the fissure. Does blood often precedes periods of more intense pain?
Btw, I'm very uncertain about what caused my reaction to rectogesic (or my application of it). Actually, I have tried to apply it only on the outside at times, but with the same adverse effect. On the other hand, applying Diltiazem inside the anus with the finger has caused similar spasms. So now I simply go for Diltiazem on the outside. But not sure it helps that much.

Did the BM hurt when you saw blood on your toilet paper? The answer to your question is yes in that blood from a fissure on toilet paper would precede pain but it also hurts at the time of the BM as well (like a cutting sensation). As you said in your post blood on toilet paper could be a number of things but I think only a fissure gives pain at the same time as the blood appearing? A better informed forum member will be able to confirm.

Sorry I can not give you the answer - I bled only once during all the time I had a fissure

I don't think there's necessarily a strict relationship between bleeding and pain. They can present together, but having one doesn't imply the other will come for sure.
When my fissure was acute, it bled A LOT (the entire toilet bowl would be pink-red after a poop) and also hurt A LOT.
After the fissure went chronic, it didn't hurt too bad, but still bled on occassion (less than during the acute phase but definitely still noticeable).
I wouldn't worry about intense pain being around the corner simply because there was some bleeding.
BTW I had a perianal abscess after surgery and had some bleeding when it partially burst. But that blood was mixed with very obvious yellow pus.
What kind of antibiotics did you get? And what kind of examination are they going to do with your colon inflated? Is it a scope or an imaging test? I would've figured that they'd already done that during your previous colonoscopy (assuming that what you're calling an "endoscopy" is indeed what I'm calling a "colonoscopy").