I think this is made by doctors for other doctors. I thought it was useful.
http://www.slideshare.net/thedukes/anal-fissure-pitfalls-in-management

Very interesting. I wish I could talk to the doctors to ask about some of the slides.
eg, slide 6, things you will miss if you don't think of looking for them - abcess, tumour, ulcer. How would you look for them? Did my doctor looks for them????
Slide 12 - why are men more likely to be offered surgery sooner?
I didn't really understand the pictures of surgery. Plus they made me feel funny!
I didn't understand the pictures on slides 34 and 41.
I thought slide 47 summed it up very well, if rather depressingly.
Thanks for posting that, aimonaali.

Slide 12 - I think it's because women are more likely to have problems with the sphichter afterwards due to giving birth, if the muscle is already damaged.
The surgery pics probably show open and closed LIS. First one being the closed one. But don't take my word for it:)
Slides 34 and 41 are ultrasound pics of the anus and apparently there's something wrong with them but you'd have to be a specialist to really understand them.
I think the thing about the tumors etc. was just that those things should be "disqualified" as the reasons for rectal bleeding and other symptoms but if you are diagnosed with a fissure, that's proably the what's causing the symptoms.
But I'm not a doctor (studying to be a radiographer though:P) so your guess is as good as mine.