The anus is that part of the intestinal tract that passes through the muscular canal of the pelvis and anal sphincters. It is the final orifice through which stool passes out of the body. In adults, the anus is 4 to 5 centimeters long. The lower half of the anal canal has sensitive nerve endings.
What can cause anal swelling?
Anal Cancer: How to Diagnose, Staging & Treatment - Dana-Farber Cancer Institute | Boston, MA
The anus is the opening at the end of your anal canal. The rectum sits between your colon and anus and acts as a holding chamber for stool. When pressure in your rectum becomes too great, the internal ring of muscle called the anal sphincter relaxes to allow stool to pass through your anal canal, the anus, and out of your body. The anus consists of glands, ducts, blood vessels, mucus, tissues, and nerve endings that can be highly sensitive to pain, irritation, and other sensations. Depending on the cause, a swollen anus can feel warm, cause sharp or burning pain especially after a bowel movement , and even produce bleeding and pus. Anal swelling can have a number of causes.
Signs and Symptoms of Anal Cancer
Anal swelling can occur for a variety of reasons. Most causes of a swollen anus are temporary and harmless, but some require medical attention. The anus is at the end of the rectum, and muscle surrounds it.
Please do not call our clinics or hospitals with questions. Hemorrhoids are swollen veins in the anal canal. This common problem can be painful, but it's usually not serious. Veins can swell inside the anal canal to form internal hemorrhoids. Or they can swell near the opening of the anus to form external hemorrhoids.