Updated: October 10, 2017
The anus is the opening at the end of the digestive tract where stool leaves the body. The anus starts at the bottom of the rectum and the anorectal line separates the anus from the rectum. The lower half of the anal canal has sensitive nerve endings. There are blood vessels under the lining, and in its mid portion there are numerous tiny, anal glands. These glands release fluid into the anus to keep its surface moist.
Anal disorders that cause anal pain and irritation are:
A tear in the lining of the anus(anoderm), often caused by constipation or after the passage of a hard bowel movement is called anal fissure. An anal fissure is also called an anorectal fissure. Anal fissures can also be developed because of prolonged diarrhea, inflammatory bowel disease or sexually transmitted diseases involving the anorectal area.
Acute or short-term anal fissures are usually superficial and shallow, but chronic or long-term anal fissures may extend deeper through the anoderm to expose the surface of underlying muscle.
An anal abscess is a swollen, painful collection of pus near the anus. They originate in a tiny anal gland, which enlarges to create a site of infection under the skin. These are mostly located near the opening of the anus but can also occur deeper or higher in the anal canal, closer to the lower colon or pelvic organs.
An abnormal channel developing between the anus and the skin of the buttocks. An anal fistula will develop after an anal abscess has drained . Sometimes the opening of the fistula at the skin surface constantly discharges pus or bloody fluid. In some cases, the opening of the fistula closes temporarily, causing the old anal abscess to flare up again as a painful pocket of pus.
Hemorrhoids can be internal or external. Internal hemorrhoids are swollen veins inside the anus or rectum. These cannot be seen from outside the body where as external hemorrhoids are blood vessels that swell near the opening of the anus or bulge outside.
Symptoms of anal disorders vary, depending on the specific anal problem.
People who suffer from constipation can have a recurrent problem of painful anal fissure. Usually superficial fissures heal quickly with medical treatment, and most symptoms disappear within a few days to a couple of weeks.
An anal abscess sometimes drains on its own and if not the doctor may incise and drain the abscess. The pain is usually immediately better after an abscess is drained. An anal abscess often turns into an anal fistula even with appropriate treatment.
If the external opening of the fistula becomes clogged and the old abscess reactivates, symptoms of a recurrent anal abscess may develop.
The pain and swelling will slowly go away over a period of days to a couple of weeks.