Why does my anus suddenly hurt?

The buttocks are rich in sensory nerves, especially the nerves near the anus, which are extremely sensitive to various stimuli, including some disease stimuli. Because the anus is a high-incidence site for intestinal diseases, it is easy to show symptoms of disease, causing endless pain to patients. For example, why does the anus suddenly hurt before and after defecation? Let’s take a look at the explanation below.

Anal fissure

The pain caused is cyclical and often occurs during or after defecation. It is mainly caused by irritation from feces and expansion of the ulcer fissure. The pain is paroxysmal burning or knife-like pain and can last for several minutes; the pain subsides after the stool passes. In addition, due to the stimulation of defecation, the internal sphincter may be in continuous spasm, causing severe and persistent pain in the ulcer fissure; it can often last for several hours, and the patient is restless and in great pain; in severe cases, the pain can last for more than 24 hours. In addition to pain, anal fissures are often accompanied by symptoms such as bleeding and constipation.

Anal sinusitis

Generally, there is slight pain and heaviness in the anus. During defecation, the stool presses on the inflamed anal sinus, causing burning pain in the anus. If the sphincter contracts due to stimulation, the pain will intensify and radiate to the buttocks and posterior thigh. It is often accompanied by a small amount of purulent or mucous secretion with a foul odor, which may cause moisture, itching and other discomforts around the anus over time.

Thrombosed external hemorrhoids

In mild cases, there is a foreign body sensation, often accompanied by bloating and pain. Due to damage to the perianal veins, blood clots form thrombi, and purple round hard nodules appear under the outer skin of the anus, usually at 3 o'clock and 9 o'clock in the lithotomy position.

Perianal abscess

The main symptom is distension and pain, and when pus forms, the pain is like a chicken pecking at the skin. Due to different factors such as the location of perianal abscess, size of abscess, pathogenic bacteria and patient's body resistance, the symptoms and signs that appear are also different. Common ones include subcutaneous abscess around the anus, ischiorectal abscess, pelvic rectal abscess, retrorectal abscess, and tuberculous abscess. Doctors at Quanzhou Boshi Anorectal Hospital pointed out that except for the different main symptoms, these abscesses generally have fever, chills, constipation, and difficulty urinating. Unlike other parts of the body, more than 90% of perianal abscesses can form anal fistulas, which have a longer course of disease.