by Scientist2516 » 11 Nov 2013, 09:17
Lmdouce, anal resting pressure is basically how tight your anus is.
The idea is, that people with a normal (fairly low) anal resting pressure are unlikely to get a fissure.
People with high anal resting pressure are more likely to get a fissure, and if they do, it is less likely to heal.
I don't think they really know why, but two possible reasons are:
1) the tightness of the muscle at rest makes it more likely to tear during a BM. To explain this a little more, our internal anal sphincter is strongly contracted almost all the time, so that we don't leak BM. To have a BM, your sphincter must relax. If it doesn't relax and you have a big BM, the skin of the sphincter can tear.
2) If the sphincter is really tightly contracted at rest (ie when you are not on the toilet), less blood can get to the area, so the area gets weak (this is called ischaemia). And then, if you do get a fissure, it can't heal because of the lack of blood supply.
The most common place to get a fissure happens to be where blood supply is lowest anyway - the back part of the anus at 6 o' clock.
So LIS is supposed to reduce anal resting pressure by cutting the anal muscle. Now, instead of a circle, it's a C shape and can't contract as strongly. The idea is to prevent painful spasms. I suppose it may also allow blood flow to the anus again.
The place they cut is away from the most ischaemic area, so a LIS cut will heal much better and faster than the fissure.
You can also increase blood supply and relax the anal sphincter with medications like nifedipine, diltiazem and nitroglycerine. These are all blood pressure drugs, which relax and open blood vessels, and relax smooth muscle like the internal anal sphincter. But if these don't work for you, LIS is usually the next step.
I hope this helps.
Nifedipine/lidocaine, no help
Diltiazem, effective, but caused major rash
Nitroglycerine, effective.
Topical estrogen for final healing.
Gentle heat to bottom - pain relief, muscle relaxant
Kondremul mineral oil
Time - lots of time.
Status - Healed!