Anoscopy: Diagnostic Procedure for Anorectal Health
Updated: 3 days ago
Medically reviewed by Dr. Baraa Alnahhal, MD · Last reviewed: October 2026
Quick Answer
Anoscopy is a medical examination that uses a specialized scope called an anoscope to view the inside of the anus and lower rectum. [1] It is mainly used to diagnose hemorrhoids, anal fissures and infections. [1] The brief office procedure usually takes a few minutes, may cause mild pressure or discomfort, and requires no advanced bowel preparation or sedation. [1]
What the research says
Treating anal precancer found through high-resolution anoscopy lowered the risk of anal cancer. In a phase 3 trial of 4,459 people living with HIV, aged 35 or older, who had biopsy-proven anal high-grade squamous intraepithelial lesions (HSIL), treating the lesions reduced progression to anal cancer by 57% compared with active monitoring (173 versus 402 cases per 100,000 person-years; 95% CI for the reduction 6% to 80%; P=0.03). All participants had high-resolution anoscopy at least every 6 months (PubMed: Palefsky et al., N Engl J Med, 2022 [2]).
Anal cytology is a reasonably useful first screen that can point people toward high-resolution anoscopy. A meta-analysis of 12 studies with 2,541 participants found that anal cytology detected anal intraepithelial neoplasia or worse with a pooled sensitivity of 0.79 (95% CI 0.77 to 0.82) and a pooled specificity of 0.66 (95% CI 0.64 to 0.69). The authors noted that people with abnormal anal cytology may benefit from high-resolution anoscopy (PubMed: Chen et al., Diagn Cytopathol, 2019 [3]).
What is Anoscopy?
An anoscopy is a diagnostic medical exam that allows a healthcare provider to look closely at the lining of the anus and the very lowest part of the rectum. [1] The procedure utilizes an anoscope, also known as an anal speculum, which is a rigid, hollow instrument typically measuring one to two inches in diameter and three to five inches in length. [1] This scope provides the illumination and access necessary to identify abnormalities that might not be visible during a standard physical examination.
For more detailed visualization, providers may perform a high-resolution anoscopy (HRA). This variation incorporates a magnifying colposcope to detect subtle cellular changes or abnormal tissues that could indicate the presence of precancerous cells.
Comparing Anorectal Exams
It is important to distinguish anoscopy from other common endoscopic procedures, as they differ in scope, depth, and preparation requirements.
Why is an anoscopy performed?
Healthcare providers recommend an anoscopy to investigate specific symptoms or to screen for conditions in patients at higher risk for anorectal diseases. Because it is a quick and effective diagnostic tool, it is often the first step in identifying the cause of anal discomfort or irregularities.
Common symptoms that warrant an anoscopy include anal bleeding, discharge, persistent itching, swelling, or the presence of lesions and protrusions. [1] The procedure is instrumental in diagnosing a wide range of conditions, including:
Hemorrhoids and Anal Fissures: Identifying swollen veins or small tears in the anal lining. [1]
Infections: Detecting anal yeast infections, abscesses, or sexually transmitted infections (STIs). [1]
Structural Issues: Visualizing anal fistulas or rectal prolapse. [1]
Cellular Changes: Screening for anal dysplasia or anal cancer. [1]
What is an anoscopy like?
The procedure is typically performed in a doctor's office or an outpatient clinic. [1] While patients are generally awake, the design of the lubricated anoscope ensures it passes smoothly through the anal canal. Most individuals describe the sensation as a feeling of internal pressure, similar to the urge to have a bowel movement or experiencing mild bloating. [1]
Procedure Steps
Preparation: Patients are positioned on an exam table, often lying on their side in a fetal position or bending forward. [1]
Digital Exam: The provider performs an initial digital rectal exam (DRE) using a lubricated, gloved finger to check for immediate abnormalities. [1]
Insertion: The lubricated anoscope is gently inserted into the anus and advanced about 2 inches into the anal canal.
Visualization: A removable plug (obturator) is withdrawn from the scope, allowing the provider to examine the tissue as the scope is slowly removed. [1]
Sampling: If necessary, the provider may use swabs to collect mucus or pus for testing, or surgical forceps to take a small tissue biopsy of any suspicious masses. [1]
What are recovery and results like after an anoscopy?
Following the exam, most patients can resume their normal activities immediately. If a biopsy was not performed, the healthcare provider can usually share the visual findings right away. [1] If tissue samples or swabs were collected, these are sent to a laboratory for analysis, with results typically following a few days later. In some instances, minor treatments, such as those for bleeding hemorrhoids, can be performed during the same visit as the diagnostic anoscopy. [1]
Frequently Asked Questions
1. Does an anoscopy hurt?
The procedure is designed to be as comfortable as possible. While the anoscope is lubricated for smooth passage, patients usually feel mild discomfort or pressure rather than sharp pain.
2. How long does an anoscopy take?
A standard diagnostic anoscopy typically takes only a few minutes. The duration may increase slightly if the provider needs to take biopsies or perform a high-resolution exam. [1]
3. Do I need to fast before the procedure?
No, fasting is generally not required. However, your provider may suggest emptying your bowels and bladder shortly before the appointment for comfort.
4. What is a high-resolution anoscopy?
A high-resolution anoscopy is a more detailed version of the exam that uses a magnifying colposcope and a specialized solution (acetic acid) to highlight abnormal cells that might be precancerous. [1]
5. Who performs this procedure?
Anoscopies are typically performed by specialists in gastrointestinal health, such as gastroenterologists or colorectal surgeons. [1]
6. Is anesthesia used for anoscopy?
Most patients do not require anesthesia. If a patient is particularly sensitive or has a severe condition, a topical numbing agent like lidocaine may be applied. [1]
7. What is an anal speculum?
"Anal speculum" is another medical term for an anoscope, the hollow, lighted instrument used to view the interior of the anal canal.
8. Can an anoscopy diagnose cancer?
Yes, it is a primary tool for detecting anal cancer or dysplasia. If suspicious tissue is found, a biopsy is taken to confirm the diagnosis in a lab.
9. Are results available immediately?
Visual findings are shared by the provider right after the exam. Results from lab cultures or biopsies take additional time to process. [1]
10. Can I drive home after the exam?
Yes, since anesthesia is typically not used, most patients are fully capable of driving themselves home and returning to their daily routine immediately.
Related Reading
Proctoscopy: A Guide to Rectal and Anal Examinations describes a related exam of the rectum and anus.
Anal Fissures: The Most Common Cause of Anal Pain — What Causes the Tear, Why It Hurts So Much, and How It Heals explains anal tears, why they hurt and how they heal.
Hemorrhoid Banding: Procedure, Recovery, and Success Rates covers a common office treatment for internal hemorrhoids.
Anal Dysplasia: The Precancerous Cell Changes Linked to HPV — and What Treatment Prevents Cancer explains precancerous anal changes found on exam.
References
Cleveland Clinic. Anoscopy: What It Is & What To Expect During the Procedure. Cleveland Clinic. May 17, 2023. https://my.clevelandclinic.org/health/treatments/24993-anoscopy
Palefsky JM, Lee JY, Jay N, et al. Treatment of anal high-grade squamous intraepithelial lesions to prevent anal cancer. N Engl J Med. 2022;386(24):2273-2282. PMID 35704479. https://doi.org/10.1056/NEJMoa2201048
Chen CC, Chou YY. Predictive value of the anal cytology for detecting anal intraepithelial neoplasia or worse: a systematic review and meta-analysis. Diagn Cytopathol. 2019;47(4):307-314. PMID 30605263. https://doi.org/10.1002/dc.24078
Medical Disclaimer
This article is for informational purposes only and does not constitute medical advice. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read here.
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