Overview of Anoscopy
Anoscopy is a quick and cost-effective procedure that your doctor can do by your bedside. It doesn’t need any specific preparation or sedation. During this procedure, the doctor can look inside the lower part of your rectum and the muscle that controls your anus.
Studies have shown that anoscopy is better at identifying certain conditions in the anus and rectum – like internal piles (haemorrhoids), inflammation of the rectum (proctitis), tears or cuts (lacerations), abnormal connections between different parts of your body (fistulas), ulcers, and lumps – than a procedure called flexible sigmoidoscopy.
Additionally, it’s important to note that half of the cases where people notice bleeding from their rectum could be wrongly thought to be due to haemorrhoids if an internal examination like anoscopy isn’t done to confirm the diagnosis.
Anatomy and Physiology of Anoscopy
The lower part of our digestive system, also known as the lower gastrointestinal (GI) tract, has some key structures we can see. These include:
- A part known as the anorectal canal, which is around 4 cm long,
- A spot in the middle of the anorectal canal known as the dentate line. This is where two types of cells in the canal change from one type to another,
- The anal glands,
- And some vertical folds along the inside of the canal, referred to as the columns of Morgagni. These end in tiny pockets or crypts that can sometimes get blocked and may get infected.
Hemorrhoids are swellings involving blood vessels, supporting tissue, and muscle that are in the left side, right front, and right back part of the anal canal. Hemorrhoids are usually painless because they are located above the dentate line where the nerve supply is not sensitive to pain. However, if they become very swollen, they may extend outside the rectum or ‘prolapse’, which can then be painful. This can also happen if the blood supply to these hemorrhoids gets cut off. Hemorrhoids, while they do cause bleeding, do not increase the occurrence of swollen veins in patients with high blood pressure in the liver (portal hypertension).
On the other hand, hemorrhoids that are below the dentate line, or “external hemorrhoids”, can often cause considerable discomfort because they are sensitive to pain. A doctor may use anoscopy, a procedure using an instrument inserted into the rectum, to identify swollen internal hemorrhoids. However, pain may prevent the use of anoscopy when there are external hemorrhoids.
Why do People Need Anoscopy
Anoscopy is a procedure that doctors use to understand potential problems causing discomfort or pain in the anus or rectum. It can also detect the presence of sexually transmitted infections or other conditions that cause bleeding, such as hemorrhoids or wounds. Besides, it also helps in checking whether a person has anal cancer, especially if they are at high risk. Men who are sexually active with other men and also have HIV are considered high-risk, with a lifetime risk of 7% to 8% if they contracted HIV in their 20s. Currently, no standard guidelines recommend routine testing for these risks.
In addition to giving doctors a good view of the anus and surrounding areas, an anoscopy also helps them observe the internal sphincter (the circular muscles around the opening of the anus). It usually comes to use when a basic physical examination, called a digital rectal examination, doesn’t provide enough information.
Here’s a rundown of the primary reasons why a person might undergo an anoscopy:
* Find the cause of rectal bleeding (from hemorrhoids, inflammation, or cancer)
* Collect cell samples to check for anal squamous lesions, which is particularly important for high-risk patients with HIV
* Check for condylomas (warts) in the anus
* Find out the cause of anal or near-anal pain (from blood clot-formed hemorrhoids, fissures/tears in the lining of the anus)
* Detect anal fistula (an abnormal tunnel between the skin near the anus and the rectum)
* Assess anal trauma or injury
* Examine a mass felt during a digital rectal exam
* Investigate reasons for itching around the anus
* Understand reasons for abdominal pain
* Analyze changes in bowel habits
* Check for anal discharge or prolapsing (bulging) of the rectum or anus
* Retrieve any foreign objects in the anus
* Deal with chronic constipation that has led to fecal impaction
* Treat hemorrhoids that are bulging out of the anus with a procedure called rubber band ligation, using a special tool called a slotted anoscope.
When a Person Should Avoid Anoscopy
There are certain situations when a medical procedure called anoscopy might not be advised. These could be:
If the person undergoing the procedure is unable to tolerate the examination due to discomfort, fear, or significant active bleeding. This is important because a big amount of bleeding might make it difficult for the doctor to see clearly during the examination.
The procedure may also be unsuitable if the person has a known lump in the end part of their rectum. The reason for this is that introducing the rigid tool used for anoscopy (called an anoscope) could potentially damage or irritate this lump.
Also, in cases where a person has an imperforate anus (a birth defect where the opening to the anus is missing or blocked), they should not undergo this procedure.
Equipment used for Anoscopy
In order to perform the examination, your doctor will need specific items such as lubricating jelly or lidocaine jelly, gloves, paper towels or tissues, a disposable sheet, a light source (if it’s not part of the instrument called an anoscope), and the anoscope itself.
Before starting the exam, your doctor will explain to you what to expect, the possible risks and benefits, as well as any other possible examination methods. This is a necessary step to ensure you understand and are comfortable with the procedure. Be prepared for some discomfort during the examination.
An anoscope is a special instrument used to look inside your anal passage. There are two styles: slotted and non-slotted, both come with an obturator or a device that blocks the view when being inserted. Once inside, the obturator is removed to allow the doctor to see inside. The non-slotted anoscope gives a full 360-degree view of the anal passage all at once. The slotted anoscope, on the other hand, allows to see only a small part of the anal opening and lower part of the rectum at a time. This might require several insertions if rotating the device is uncomfortable for you.
Most anoscopes available for use do not have a built-in light source. Therefore, your doctor will either use a light mounted on their forehead or have an assistant aim the light to ensure they have a clear view. There is a more specialized examination method called high-resolution anoscopy, which uses a camera for a magnified view. However, this is usually performed only by experts who have received specialized training.
Preparing for Anoscopy
Before the procedure, numbing medication is applied in the anal area. This medication, known as topical anesthesia with 2% lidocaine jelly, needs to be in place at least 10 minutes before the anoscope (the tool used in the procedure) is inserted. If the patient needs additional comfort measures, medication like morphine or drugs like lorazepam, diazepam, midazolam – which can cause sleepiness and relief from pain – may be given through an IV (a tube inserted into a vein). In some cases, doctors might use other types of drugs for IV sedation – these could include medications like fentanyl, midazolam, propofol, ketamine, or etomidate.
Before the procedure, the doctor will position the patient in a way that makes the procedure easier to perform. Usually, the patient is asked to lie on their side with the leg on the opposite side of the body bent at the knee and hip. However, there are other positions that can be used too. Some patients might be asked to kneel with their shoulders touching the examination table, or lie on their stomach.
How is Anoscopy performed
Usually, the doctor will first do a simple check by finger (digital rectal exam) to make sure that there’s nothing like a growth or tissue blocking the anal passage which could get injured when the device is put in. There isn’t enough scientific evidence to say if putting painkiller cream (like lidocaine) on the skin around the anus before the examination (anoscopy) helps to reduce pain, but some doctors do this if you’re not allergic to lidocaine. They will make the anoscopy device slippery with a special water-based gel to help it go in more comfortably. The same slippery gel could also be mixed with the painkiller cream, spreading the cream along the path where the device will go.
Normally, the anoscopy device has a part called an obturator which is inserted first and then taken out. This lets the doctor see inside your anal passage and the lower part of your rectum as they slowly pull the device out. For special types of anoscopy devices that have slots and only allows the doctor to see part of the inner lining of your anal passage at a time, they put the obturator back in again before moving the device around or putting it in further, otherwise it might be uncomfortable for you. This is because tissue can bulge into the slotted part and be pulled or pinched as the device is moved.
Possible Complications of Anoscopy
After a medical examination, some people might feel uncomfortable. Other possible issues include damage to the skin near the anus or to tissue in the hemorrhoids, which are swollen veins in the rectum. Sometimes, an infection might happen after the procedure, but this doesn’t happen very often.
To make sure people are comfortable and to prevent any damage, doctors use a safe amount of lubrication during the examination. Even though infections are very rare, doctors can sometimes give antibiotics beforehand to people who are at a high risk of infection. Extra care is needed for people who have had anal surgery before or who have anal fissures, which are small tears in the lining of the anus.
What Else Should I Know About Anoscopy?
Anoscopy is a procedure used by doctors to detect conditions like internal hemorrhoids, proctitis (inflammation of the rectum lining), or ulcers in the lower part of your rectum. It is often used when patients complain of discomfort or bleeding. This procedure is more effective than a digital rectal exam (an examination done by hand) in diagnosing these problems.
However, it’s essential to know that anoscopy has some limitations. Even though it is excellent in spotting issues like internal hemorrhoids, it cannot entirely rule out the presence of upper gastrointestinal (digestive system) bleeding. The doctor can only confirm this condition through a separate procedure called an endoscopy. In fact, around 50% of the time, a patient with rectal bleeding could also have an upper GI bleed.
Overall, anoscopy is a valuable procedure used as an initial check for rectum-related issues. It is a quick, inexpensive method that doesn’t need much preparation. But keep in mind that the presence of lower rectum problems detected through anoscopy does not exclude bleeding in the upper part of the digestive system. As a result, doctors should use anoscopy but not entirely depend on it when evaluating a patient with rectal bleeding.
