A simple algorithm is in order:
Anal Pain - most likely diarrhea related - which results in over cleaning the area - take Pepto-Bismol, stop the soap and washcloth - in two weeks better or see a surgeon
Anal Bleeding -most likely hemorrhoids or cancer - see a surgeon
Anal Pain and bleeding - short term - most likely a fissure - take a high fiber diet and will resolve in 2 weeks if not better see a surgeon
Anal Lump - acute quick appearance - thrombosis hemorrhoid resolves in one month if not see a surgeon
Anal Leakage - most likely diarrhea related take Pepto-Bismol stop over cleaning the skin and start a high fiber diet if no resolution in 2 weeks see a surgeon
Anal Pain and lump lasts days - most likely an abscess or fistula see a surgeon
Diagnosis of diseases of the anus:
Begin by looking and then by feeling the anus.
The anus is generally a smooth flat area with all crevices gathering to form a star with a central hole the anal canal.
This narrowed canal is narrowed not because of a conscious effort to close the anus but rather because of the work of a muscle called the internal anal sphincter. This muscle is in constant tone and is a smooth muscle like the heart muscle. The internal anal sphincter works all by itself. When the anus is closed there is still a small hole present and if the hemorrhoidal cushions were absent that generally fill this defect in the anal canal the anus would leak gas.
Skin of the anus is called the anoderm. The anoderm is as sensitive as the cornea of the eye and is easily torn by trauma. The anoderm covers the internal anal sphincter and often the skin is so thin that the brown muscle underneath can be seen through the skin. When the skin ends it comes into an area of mucousa that has mounds call hemorrhoidal cushions which provide sensation in the anal canal and provide continence to gas.
In the anal canal there is a transition zone which changes from skin to a mucous membrane. This is where the hemorrhoidal cushions reside. Another transition zone of the body is the mouth and the lips are the site where the skin ends and the mucousa begins. In the anal canal the lips are called the dentate line and instead of nice pink lips there is an uneven border which is somewhat wavey, the waves sometimes looking like small teeth. The pleating of the mucousa gathering into the narrowed anal canal is reminiscent of a curtain gathering tightly together with pleats at the base. The pleats in the anal canal can form pockets where the skin and the mucousa come together and these pockets are potential spaces or crypts than can be the origin of a fistula from the anus to the skin outside. When this occurs it is called cryptoglandular disease.
The hemorrhoidal cushions are located in a triangle in the anal canal. There are two on the right and one on the left. They are called the right anterior, the right posterior and the left lateral hemorrhoidal cushions or columns. They swell to protect the anus from violent stool which is too soft or too hard. The hemorrhoids protect the delicate skin of the anus. The hemorrhoids also warn the anus that stool or gas is coming and with the warning to the external anal sphincter (a muscle the human has control of) the human can control the passage of gas or stool.
Interestingly the hemorrhoids will not warn of the approach of diarrhea. Diarrhea is an enemy of the body and needs to be gotten rid of immediately so the anus gives no warning of diarrhea so the external anal sphincter generally will not be given enough warning to stop the flow.
The pathology of the anus is based in this anatomy. The anus can bleed, itch, have pain and leak both mucous and stool. The anoderm should be dry. There should be no redness and no punctate lesions on the outside of the anal canal. Any lump or bump or lesion should be evaluated by a physician. Multiple lumps that are small are often anal warts. Soft lesions that are less than three in number are usually skin tags. Purple firm but soft round bumps are generally thrombosed hemorrhoids. Hard lumps are either scar tissue from a fissure or cancer.
Most all of the problems of the anus can be treated with a high fiber diet and having a normal stool.
If there is a lump and it does not go away in 2-4 weeks seek the advice of a surgeon and ask for a biopsy of the lesion.