Anoscopy and high-resolution anoscopy

Anoscopy examines the anus and lower anal canal using a short, hollow instrument called an anoscope.

High-resolution anoscopy, or HRA, adds magnification. A colposcope remains outside your body while dilute acetic acid and sometimes iodine are applied to highlight abnormal tissue. Unusual areas may be biopsied for laboratory testing or treated during HRA or at a later appointment.

Neither procedure examines the rectum or colon as fully as sigmoidoscopy or colonoscopy.

Standard anoscopy may investigate:

• Anal bleeding, pain, itching, discharge, or a lump
• Suspected haemorrhoids, fissures, warts, inflammation, or growths
• An abnormal finding during an external or finger examination
• Healing or recurrence after treatment

HRA is mainly used to identify anal cell changes linked to human papillomavirus, or HPV. It may follow an abnormal screening result or previous HPV-related disease.

A high-grade squamous intraepithelial lesion, or HSIL, contains significantly abnormal cells that may progress to cancer. HSIL is not cancer.

HRA is usually offered when screening results, symptoms, immune health, previous HPV-related disease, or local guidance indicate that a detailed examination is needed.

The procedure may need to be delayed or changed if you have:

• Severe anal pain
• Acute infection or significant inflammation
• Recent anal or rectal surgery that has not healed
• A bleeding disorder or low platelet count, especially before biopsy
• Medicines that increase bleeding risk
• A condition that makes the required position unsafe

Blood thinners like warfarin or apixaban do not always prevent anoscopy, but they may affect whether biopsy or treatment is performed. Do not stop them unless the clinician managing them gives clear instructions.

Sedation or general anaesthesia may be considered if an office examination would be too painful or difficult.

Follow your facility’s instructions because preparation varies for standard anoscopy, HRA, biopsy, treatment, and sedation.

Most procedures without sedation require neither fasting nor full bowel preparation. You may be asked to use an enema so stool does not obstruct the view. Tell the team if an enema would be painful or unsafe.

Before the appointment:

• Provide an up-to-date list of medicines and allergies
• Ask what to do about blood thinners and medicines affecting platelets
• Mention pregnancy, recent surgery, infection, or severe anal pain
• Follow instructions about suppositories or inserting anything into the anus
• Arrange transport if sedation or general anaesthesia is planned

Repeated enemas or laxatives are not usually needed unless instructed.

You usually lie on your side with your knees bent, although some procedures are done on your back with your legs supported.

The clinician examines the surrounding skin and may use a gloved, lubricated finger to check for tenderness or a lump. A lubricated anoscope is then gently inserted to hold the canal open. You may feel pressure, fullness, or an urge to have a bowel movement.

During HRA, acetic acid and sometimes iodine are applied with a swab. The external colposcope provides light and magnification.

If biopsy is needed, local anaesthetic may be used before a small tissue sample is removed. You may feel brief pinching, pressure, or cramping. Bleeding is usually controlled before the anoscope is removed. Some clinics also use cautery, ablation, or another method to destroy abnormal tissue.

Mild soreness, pressure, cramping, or light bleeding may occur, particularly after biopsy or treatment. Use only pain medicine recommended by your healthcare team.

You can usually eat, drink, walk, and do light activities immediately if you did not receive sedation. Follow specific food and fluid instructions after sedation or general anaesthesia.

After biopsy or treatment, you may need to avoid strenuous exercise, receptive anal sex, tampons, suppositories, and other anal insertion until the area heals.

You may drive after an examination without sedation if you feel comfortable and your facility permits it. Do not drive after sedation or general anaesthesia; arrange for an adult to take you home.

Many people return to work the same day or next day, although treatment, several biopsies, sedation, or physical work may require longer.

Temporary discomfort and minor bleeding are common. Biopsy and treatment increase soreness and bleeding risk.

Other possible complications include:

• Infection
• Faintness during the examination
• A reaction to local anaesthetic or another product
• Scarring or narrowing after extensive treatment
• Missed abnormal tissue or an inconclusive sample

Heavy bleeding or severe injury is not expected. Tell the clinician immediately if pain becomes difficult to tolerate. You can ask them to pause or stop.

The clinician can usually explain the visual findings immediately. These may include normal tissue, haemorrhoids, a fissure, warts, inflammation, or an area requiring laboratory testing.

Biopsy results usually take several days. They may show no significant abnormality, low-grade changes, HSIL, another condition, or cancer. Cancer can only be diagnosed after tissue is examined by a pathologist.

Follow-up may involve observation, repeat HRA, treatment, or specialist referral. Timing depends on the biopsy result, whether abnormal areas were treated, and your health history.

Confirm how results will be delivered and whom to contact if they do not arrive when expected.

Alternatives depend on why anoscopy was recommended.

Visual and digital rectal examinations involve no instrument but may miss small or flat changes. Anal cytology collects cells with a swab but cannot locate abnormal tissue or confirm a diagnosis; abnormal results may still require HRA and biopsy.

Standard anoscopy is quicker and more available than HRA but lacks magnification for subtle HPV-related changes. Sigmoidoscopy and colonoscopy inspect farther into the bowel but do not replace HRA for detailed assessment of anal cells.

Examination under anaesthesia may be suitable if an awake procedure is not possible, but it requires fasting, transport, and more recovery time.

Observation avoids the procedure now, but abnormal tissue may remain unidentified or untreated. Ask about the risks of waiting and which changes require earlier assessment.

Light spotting after biopsy or treatment may be expected. Contact your healthcare team during routine hours if:

• Bleeding lasts longer than expected
• Pain is not improving or interferes with normal activities
• You develop increasing swelling, discharge, or difficulty passing stool
• You have questions about wound care, activity, or medicines
• Results do not arrive by the date provided

Seek urgent medical care for heavy or persistent bleeding, severe or rapidly worsening pain, fever with increasing anal pain, fainting, marked weakness, or difficulty passing urine.

Call emergency services for uncontrolled bleeding, collapse, severe breathing difficulty, or signs of a serious allergic reaction.

Will I be asleep for an anoscopy?

Usually not. Local anaesthetic may be used for biopsy. Sedation or general anaesthesia may be offered for extensive treatment or if an awake examination is unsuitable.

Can I drive home afterward?

Often, if you had no sedation and feel comfortable. You cannot drive after sedation or general anaesthesia.

How painful is anoscopy?

Pressure, fullness, or an urge to have a bowel movement is more common than sharp pain. Biopsy may briefly pinch or cramp. Existing fissures or inflammation can increase discomfort.

When will I know the results?

Visual findings are usually discussed immediately. Biopsy results take several days or longer, depending on the laboratory.

Is anoscopy the same as a colonoscopy?

No. Anoscopy examines the anus and lower anal canal. Colonoscopy uses a longer flexible camera to examine the rectum and colon and requires bowel preparation.

Does an abnormal HRA result mean I have cancer?

No. Many abnormal findings are not cancer. Biopsy identifies the type and grade of change. HSIL is precancerous, not cancer.