Approach to adult patients with anorectal complaints

INTRODUCTION — Anorectal complaints are common: hemorrhoid-related complaints account for more than two million outpatient evaluations annually [1,2], and the incidence of anal fissure is estimated to be 1.1 cases per 1000 person-years [3]. It is, therefore, highly likely that clinicians will encounter these conditions.

As added challenges, many anorectal diagnoses share similar symptoms, and benign anorectal conditions share common symptoms with cancers of the anus and rectum. As such, a thorough evaluation is critical toward making the correct diagnosis.

This topic describes how to perform a thorough history and physical examination for adult patients presenting with various anorectal complaints, followed by key points to consider depending upon the patient's chief complaint (eg, pain, bleeding).

Specific anorectal diseases are discussed in other UpToDate topics referenced below.

PATIENT HISTORY — The clinician should first elicit a history of anorectal bleeding, anorectal or perianal pain, perianal drainage, anal pruritus, or the prolapse of tissue through the anal orifice. The patient response will help direct the subsequent evaluation. (See 'Symptom-based differential diagnosis' below.)

Additionally, the patient's bowel habits should be discussed, including the average number of bowel movements per day, the need for moderate or severe straining to defecate, the average number of minutes required per defecatory episode, the cleaning routine, and any bowel regimen the patient may use.

The patient should also be inquired about unintentional weight loss, changes in bowel habits, and recurring abdominal distention or abdominal pain. Patients with recurring abdominal pain and/or diarrhea should be asked about a family history of inflammatory bowel disease.

Regardless of age, patients should be questioned about prior endoscopic examinations of the large intestine (sigmoidoscopy or colonoscopy). Whether the patient has had a recent colonoscopy may adjust the examiner's degree of concern regarding possible malignant etiology of the anorectal bleeding.

PHYSICAL EXAMINATION — Many benign and malignant anorectal diseases present with similar symptoms, making physical examination critical in providing a diagnosis and in directing further evaluations.

Anatomy and terminology — While a detailed understanding of anorectal anatomy is not required to perform an adequate anorectal examination, it is helpful to understand certain anatomical terminology.

The anal canal represents the distal 3.5 to 4 cm of the alimentary tract (figure 1). It is separated into two halves by the dentate line, each half with a distinct embryonic origin, creating a distinct histology and a distinct innervation. The distal half of the anal canal is lined with a modified form of skin referred to as anoderm, which receives somatic innervation, which renders anal canal tissue distal to the dentate line sensitive to painful stimuli. The anal canal proximal to the dentate line is lined with columnar epithelium, which is similar to the mucosa of the adjacent rectum. The proximal anal canal receives autonomic innervation, which renders tissue insensate to painful stimuli (and is the basis for rubber band ligation of internal hemorrhoids being a procedure tolerable for unsedated patients).

●Lesions that are not completely visible while separating the gluteal cheeks are appropriately referred to as anal lesions.

●If a lesion can be completely visualized with separation of the gluteal cheeks, and if it is within 5 cm of the anal orifice, this lesion would be classified as a perianal lesion.

●Any lesion more than 5 cm from the anus would be considered a skin lesion unrelated to anorectal pathology.

The rectum is the continuation of the sigmoid colon leading to the anal canal (figure 2). The boundary between the rectum and the anal canal is usually determined endoscopically.

Patient positioning — The in-office anorectal examination is best performed in the "prone-jackknife" position, which not only provides optimal visualization but also aligns the laterality of the examiner with the patient.

However, many medical offices do not have a dedicated examination table to allow patients to assume this position. In that scenario, the lateral decubitus position is an acceptable alternative for an awake anorectal examination in most patients.

Complete anorectal examination — A complete anorectal examination consists of inspection, digital rectal examination, anoscopy/proctoscopy, and endoscopy. The first three parts are usually achievable in any office setting; endoscopy (ie, sigmoidoscopy or colonoscopy) requires additional equipment or personnel.

Inspection — The clinician should first gently separate the buttock cheeks to visualize the perianal skin (the 5 cm perimeter surrounding the anal orifice). The examiner should denote any gross lesions concerning for anal cancer, perianal abscesses and/or anal fistulas, or external hemorrhoids. Any other discrete skin lesions (eg, skin excoriation, condyloma) should also be recorded, including their anatomic location and distance to the anal orifice.

Digital rectal examination — A digital rectal examination should be performed with adequate lubrication, and the clinician should communicate to the patient throughout the examination to optimize patient comfort and compliance.

A digital rectal examination can evaluate for any mass in the anal canal or lower rectum or a stricture secondary to prior surgeries or Crohn disease. Neither anoscopy nor proctoscopy can replace a digital anorectal examination as the distal anal canal is difficult to visualize with an end-viewing endoscope and the introduction of an instrument may obscure a distal lesion that the instrument is trying to detect. Such distal lesions are best detected by the digital rectal examination.

If an anal fissure is suspected by inspection or by point tenderness upon insertion of the tip of a gloved finger, digital rectal examination should be deferred until healing as it would unnecessarily provoke the patient's anal pain. (See 'Localized perianal pain' below.)

In addition to evaluating for palpable abnormalities, digital anorectal examination also allows for a general assessment of pelvic floor and anal sphincter function, which can be helpful in patients with complaints of constipation and/or incomplete anorectal evacuation. (See "Etiology and evaluation of chronic constipation in adults".)

●Both the resting and voluntary anal sphincter tone can be assessed by a digital rectal examination, the latter by instructing the patient to "tighten" the external anal sphincter as they would while resisting the urge to defecate or flatulate.

●The puborectalis muscle can be identified by palpation at the anorectal junction, and in patients with functional pelvic floor abnormalities, palpation of this muscle often reproduces a milder form of the patient's presenting complaints of pelvic pain or pressure. With the examining digit in this location, a Valsalva maneuver by the patient, as occurs during defecation, should produce relaxation of the puborectalis muscle, with the muscle moving toward the sacrum. The absence of relaxation, or paradoxical contraction, can be noted in functional pelvic floor conditions. Additionally, the same Valsalva maneuver should be associated with relaxation of the internal anal sphincter; paradoxical contraction of this muscle can be an indication of anal sphincter dyssynergy.

Anoscopy or proctoscopy — Anoscopy or rigid proctoscopy should be performed when instruments and trained providers are available. The instruments that provide the best visualization have built-in light sources, some of which are battery powered (portable). The patient should ideally be placed in a prone jackknife position for superior examination of the perianal skin and greater ease of introducing the instrument, though the lateral decubitus position is also adequate. For patient comfort, the instrument should be generously lubricated before insertion, preferably with warmed lubricant.

An anoscopy is helpful for evaluating for anal condylomata, anal neoplasms, internal hemorrhoids, and anal fissures. A rigid proctoscopy is appropriate for identifying the location of rectal neoplasms as well as evaluating for proctitis.

If an anal fissure is suspected by inspection or attempted digital examination, anoscopy or proctoscopy should be deferred until healing as it would unnecessarily provoke the patient's anal pain. (See 'Localized perianal pain' below.)

Endoscopy — An anorectal examination is not complete without endoscopy. Clinicians should never make assumptions that anal bleeding is secondary to benign anorectal diseases (eg, hemorrhoids), which could lead to a missed diagnosis of colorectal cancer.

It is recommended that for any patient with anal bleeding, a discussion regarding endoscopy be undertaken and documented. For complaints of anorectal bleeding or abdominal pain, a colonoscopy is preferred to sigmoidoscopy because diseases such as colorectal polyps and cancers from any portion of the large bowel can cause these symptoms. If a patient has undergone a recent colonoscopy, and/or if the patient's complaints are isolated to the pelvis (eg, pelvic pain), then a more limited endoscopic examination, such as a sigmoidoscopy, may be adequate.

Examination under anesthesia — Patients are frequently anxious about awake anorectal examination, and past experiences with physically painful anorectal examinations are a frequent contributor to this apprehension. Thus, if the provider cannot achieve a thorough examination, or if certain invasive tests (eg, biopsy) are required, it may be more prudent to perform the examination under anesthesia in an operating room.

SYMPTOM-BASED DIFFERENTIAL DIAGNOSIS

Pain — The clinician should first clarify whether the pain is perianal or anal in location, and if perianal, the exact location(s) of the pain. (See 'Anatomy and terminology' above.)

Perianal pain

Generalized perianal pain — Generalized perianal pain can be caused by pruritus ani, especially when the perianal skin appears grossly normal or with minimal changes, since pruritus ani relates to hypersensitivity of cutaneous nociceptive nerves as opposed to skin changes. (See "Approach to the patient with anal pruritus".)

Generalized perianal discomfort is less likely to represent a neoplastic process than is localized perianal discomfort.

Localized perianal pain — Localized perianal discomfort can be related to skin trauma, external hemorrhoids, perianal abscess, or perianal neoplasms. Perianal condylomata do not cause discomfort.

●Thrombosed external hemorrhoids are a very common cause of localized perianal pain. Their appearance establishes the diagnosis, with enlarged and tender perianal lesions (picture 1) that could cause ulceration of the overlying skin (picture 2) and/or extrude clot (picture 3). If the patient is evaluated within 72 hours of the thrombosis, the clinician can consider a bedside incision and thrombectomy, though this intervention is associated with the risk of recurrences. If the patient presents after 72 hours, operative intervention is usually avoided since the patient's discomfort will soon begin to noticeably improve. Regardless of time of presentation, if nonviable skin is noted with a thrombosed external hemorrhoid, urgent surgical consultation is required. (See "Surgical treatment of hemorrhoidal disease", section on 'Thrombosed external hemorrhoids'.)

●Perianal abscesses can create perianal discomfort, often associated with other symptoms such as fevers or perianal drainage. Physical examination frequently reveals erythema of the overlying skin, with or without induration and/or fluctuance (picture 4). For most perianal abscesses, an incision and drainage procedure is required urgently. (See "Perianal and perirectal abscess".)

Anal canal pain — Discomfort arising within the anal canal may be related to anal fissure, anal cancer, or anal ulceration caused by sexually transmitted infections. Internal hemorrhoids generally do not cause anal pain.

●Anal fissure should be suspected in patients who complain of severe anal pain but have no visible perianal source of discomfort. Pain from an anal fissure may be constant but further exacerbated by defecation. In such patients, gentle digital palpation of the anal verge (the skin surrounding the anal orifice) at the posterior or anterior midline may identify point tenderness, which is sufficient to establish a provisional diagnosis (picture 5). A complete insertion of an examining digit or an anoscope should be avoided under these circumstances. In one to two subsequent visits (four to eight weeks), an interval digital rectal examination/anoscopy may be performed once the patient's anal pain has improved or resolved with medical therapy. (See "Anal fissure: Clinical manifestations, diagnosis, prevention".)

●Anal cancers can produce symptoms similar to those of an anal fissure, mandating that a digital anal examination be performed as part of the evaluation, though not necessarily at the initial encounter when the pain may make a digital examination unbearable. (See "Clinical features and staging of anal cancer".)

Bleeding — Bleeding is a common complaint in patients with anorectal problems.

●Bleeding from the anal canal can be secondary to diseases, including anal fissures, internal hemorrhoids (external hemorrhoids are generally not a source of bleeding except when thrombosed and extruding clot), or anal neoplasms.

•A digital anorectal examination can detect palpable neoplasms in the anal canal.

•An anoscopy is helpful in evaluating for enlarged or bleeding internal hemorrhoids (figure 3) and, if indicated, facilitating rubber band ligation or other treatments of internal hemorrhoids (picture 6). (See "Home and office treatment of symptomatic hemorrhoids", section on 'Rubber band ligation'.)

•If bleeding is accompanied by severe anal pain provoked by defecation, an anal fissure may be present. (See "Anal fissure: Clinical manifestations, diagnosis, prevention".)

●Again, it is important to remember that without a colonoscopy, a malignancy in the large intestine cannot be definitively excluded. Therefore, all patients who present with anorectal bleeding should undergo a diagnostic colonoscopy, unless there is a compelling reason to omit this examination (such as a colonoscopy within three to five years, and preferably with this prior colonoscopy having been performed when the patient was already experiencing bleeding). Young adult age is not a reliable reason for omitting a colonoscopy in these circumstances. In some studies, the incidence of colorectal cancer is rising in patients younger than 50 years of age [4]. (See 'Endoscopy' above and "Approach to minimal bright red blood per rectum in adults", section on 'Approach to the patient'.)

Prolapsing tissue — Patients may complain of a "lump" at the anus that is either present continuously or "comes and goes." Patients who complain of tissue prolapsing from the anal canal most often have either prolapsing internal hemorrhoids or rectal prolapse. One of the most reliable methods of distinguishing the two involves the patient sitting on a commode in clinic, straining as they would during the act of defecation in an attempt to reproduce the symptom for the clinician to visualize.

●Rectal prolapse has a distinct appearance, with prolapsed rectum often demonstrating concentric folds involving tissue that occupies the circumference of the anal canal (picture 7). (See "Overview of rectal procidentia (rectal prolapse)".)

●Prolapsing internal hemorrhoids often appear in "clusters" that are predominantly within quadrants surrounding the anal orifice (picture 8). The tissue has a grossly distinct appearance from rectal mucosa, and if the prolapse is chronic, the tissue may demonstrate a thicker, squamous, and almost verrucous appearance due to squamous metaplasia. Prolapsing internal hemorrhoids may reduce spontaneously or require manual reduction. In the most severe cases, prolapsing internal hemorrhoids may be irreducible. Patients with enlarged internal hemorrhoids are very likely to also have some degree of external hemorrhoidal enlargement, and since external and internal hemorrhoids are separated by only a few centimeters, it may be difficult to distinguish prolapsing internal hemorrhoids from enlarged external hemorrhoids. (See "Hemorrhoids: Clinical manifestations and diagnosis".)

Young and/or nulliparous female patients may develop either prolapsing internal hemorrhoids or rectal prolapse due to chronic constipation. Straining at defecation can cause stretch pudendal neuropathy, which can lead to the anal canal to open more than normal. This can then allow anal canal tissue, including internal hemorrhoids, to momentarily prolapse or give the sensation of prolapse. In such patients, the treatment should be focused on the underlying constipation. (See "Management of chronic constipation in adults".)

Pruritus — Anal pruritus is perhaps the most difficult complaint to manage as it is frequently associated with idiopathic causes. The patient should be queried about the laterality and exact location of the symptoms, although pruritus is often a generalized, circumferential complaint. Although patients often complain of intense itch, burning, or irritation, the perianal skin frequently appears grossly normal. This discrepancy between symptoms and physical findings reflects cutaneous hypersensitivity of nociceptive fibers in the setting of idiopathic pruritus ani. (See "Approach to the patient with anal pruritus".)

Perianal drainage — Perianal drainage can be caused by anal fistula, fecal incontinence, and other skin conditions such as pilonidal cyst, perianal hidradenitis, and perianal skin cysts (eg, sebaceous cyst).

●Anal fistula can produce either purulent or serosanguinous drainage. The presence of an anal fistula is associated with a nodular, discrete opening within the perianal skin (picture 9). Any associated symptoms, such as erythema, induration, or fluctuance, should be noted as fistulas that are not draining adequately can lead to abscess formation. (See 'Localized perianal pain' above.)

●Fecal incontinence, if predominantly involving a mucoid discharge, can be described by patients in terms similar to those fitting an anal fistula. Examination in this setting would reveal no evidence of an anal fistula, but diminished resting sphincter tone. (See "Fecal incontinence in adults: Etiology and evaluation".)

●Pilonidal diseases usually present with symptoms of pain and/or drainage (picture 10). However, drainage from a pilonidal cyst can usually be traced to the gluteal cleft rather than the perianal area. (See "Pilonidal disease".)

●Perianal hidradenitis can produce perianal drainage that is either purulent or sanguineous. This disease is also characterized by discomfort, both from chronic inflammation as well as from local abscess formation that may require incision and drainage. Hidradenitis can be diagnosed by the presence of subcutaneous sinus tract formation, often with an arborizing system of tracts (picture 11). (See "Hidradenitis suppurativa: Pathogenesis, clinical features, and diagnosis".)

●Other perianal skin lesions such as sebaceous cysts can be associated with drainage if secondarily infected. Just as in other areas of the body, sebaceous cysts in the perianal area are associated with a well-circumscribed, often raised area that may demonstrate a central punctum (picture 12). (See "Overview of benign lesions of the skin", section on 'Cysts'.)

SOCIETY GUIDELINE LINKS — Links to society and government-sponsored guidelines from selected countries and regions around the world are provided separately. (See "Society guideline links: Hemorrhoids" and "Society guideline links: Anal fissure" and "Society guideline links: Rectal prolapse".)

SUMMARY AND RECOMMENDATIONS

●Overview – Anorectal complaints are common but difficult to manage because of overlapping symptoms. A thorough history and anorectal examination are key to both diagnosis and directing further evaluation. (See 'Introduction' above.)

●History – A focused patient history should inquire about possible anorectal bleeding, anorectal or perianal pain, perianal drainage, anal pruritus, or the prolapse of tissue through the anal orifice. The elicited chief complaint will help direct the subsequent evaluation. (See 'Patient history' above.)

●Physical examination – A complete anorectal examination consists of inspection, digital rectal examination, anoscopy, and endoscopy. The first three parts are usually achievable in any office setting; endoscopy (ie, sigmoidoscopy or colonoscopy) requires additional equipment and personnel. (See 'Physical examination' above.)

●Symptom-based differential diagnosis – Evaluation based on the chief complaint is described for pain, bleeding, prolapsing tissue, pruritus, and perianal drainage above. Individual anorectal diseases are discussed in other UpToDate topics referenced above. (See 'Symptom-based differential diagnosis' above.)