Anal Fistula Differential Diagnosis: What Else Could It Be?
Your anal area is sore and swollen. It's even been leaking some blood and pus. What could it be?
It might be that you have an anal fistula, but you could also have a different anorectal condition. To learn more about the possibilities, check out this anal fistula differential diagnosis guide.
Other Anorectal Conditions that Can Be Mistaken for Anal Fistula
An anal fistula, also known as fistula-in-ano, typically begins with an infected gland. The infection progresses and results in an unnatural tract that leads from the interior anal wall to the exterior wall of the anus. Symptoms can include:
However, a number of other conditions can cause similar symptoms. Therefore, if you are experiencing anorectal discomfort, it is important to consider the possibility that your symptoms are caused by another condition on this anal fistula differential diagnosis list.
Perirectal Abscess
Just like anal fistulae, abscesses in this region usually begin with a gland infection. In fact, fistula-in-ano may develop from an abscess that progresses.
Unlike a fistula, an abscess is not a two-ended tract. A single-ended tract leads to a cavity in the tissue.
Even still, the two conditions share many similar symptoms, including pain and swelling. A fistula may be more likely to present with drainage, however.
Hemorrhoids
Some people assume that if they have anal bleeding or irritation, they must have hemorrhoids. Hemorrhoids can also cause itching, discomfort and pain. Of course, these two conditions are in actuality quite different. Fistulae involve a tract that goes into the anorectal tissue, and hemorrhoids involve swollen veins that protrude out of the rectal wall.
See examples of the two conditions in the video below:
Anal Fissure
A tear in the skin of the anal wall is known as an anal fissure. Because it involves an opening in the skin, it may be mistaken for fistula-in-ano. However, a fissure does not extend into a tract or have an outer opening.
Overlapping symptoms are another reason that anal fistulae may be mistaken for anal fissures. One of the primary symptoms of fissures is pain, which can often be extreme. Fissures may also bleed.
Proctitis
Having an inflammed rectum is known as proctitis. This is a general term that encompasses inflammation with a number of different causes. These can include:
As with fistula-in-ano, proctitis can be the cause of pain, particularly during a bowel movement. Discharge can accompany proctitis; it might be blood or mucus.
It isn't unusual to have both proctitis and a fistula. The sores and irritation of proctitis can lead to the development of anal fistulae.
Pilonidal Sinus
Pilonidal disease involves another type of unnatural tract through the tissue of the anorectal region. One common theory is that these channels are caused by hair and debris that become trapped in a pocket and lead to an infected abscess and tunnel.
Blood and pus are common symptoms associated with a pilonidal sinus. As with fistula-in-ano, this discharge can have a foul odor. Pilonidal disease can also lead to pain, swelling, skin irritation and a general feeling of being unwell.
Pilonidal sinuses are usually restricted one particular segment of the anorectal region, however. They originate near the cleft of the buttocks. Also, the pilonidal tract does not have a second opening at the outside of the anus.
Cancer
There are several types of cancer that affect the anorectal region, including lymphoma and anal squamous cell carcinoma. Approximately 50 percent of patients with anorectal cancers notice bleeding as an early symptom. Additionally, the anal area may feel sore, painful or itchy.
In addition to understanding that some cancer symptoms can overlap with the signs of anal fistulae, it is important to know that fistulae and cancer can be related. Having an anal fistula may have a greater risk of developing cancer, or a fistula can appear as a symptom of cancer.
Tests and Procedures to Confirm an Anal Fistula Diagnosis
To diagnose a fistula and distinguish it from other conditions, a doctor will perform an in-office exam. The doctor will look for an external opening and may perform a digital rectal exam. An anoscope can help the medical team visualize the rectal wall, and a fistula probe can be guided through the fistula tunnel.
If further testing is needed, the doctor may perform an MRI, an ultrasound or an x-ray. Contrast dye can help show where the tunnel is.
Anal fistulae are common in patients with an inflammatory bowel disease, particularly Crohn's disease. If a doctor suspects that you have multiple fistulae, it may be recommended that you have a scope performed to look for signs of Crohn's, especially if you have other symptoms, such as abdominal pain or chronic diarrhea.
Anal swelling, pain and bleeding are nothing to mess around with. If you're experiencing symptoms that could be caused by an anal fistula, making a doctor appointment is a must. Your doctor will perform an anal fistula differential diagnosis to determine the cause of your symptoms.
As with all medical issues, your physician is the ultimate source as to what procedure best fits your needs. Discuss all options and get a second opinion if you have any doubts. These articles are intended to be a source of general information only.
