AOBPr Proctology key terms

The short terminal segment of the digestive tract, roughly 3 to 4 cm long, extending from the anorectal junction to the anal verge and lined by a transition from glandular mucosa to anoderm.

A scalloped landmark at the mid anal canal marking the junction of columnar rectal mucosa above and squamous anoderm below, and the level at which anal glands typically open into crypts.

The hairless, gland-poor squamous lining of the distal anal canal below the dentate line, richly supplied with somatic sensory nerves, which is why distal anal pain is sharp and well localized.

The overlapping muscular ring formed by the involuntary internal anal sphincter and the voluntary external anal sphincter, plus the puborectalis, which together maintain fecal continence.

A smooth-muscle continuation of the rectal circular layer that provides most resting anal tone and is under autonomic, not voluntary, control; it is the muscle divided in a lateral internal sphincterotomy.

A striated, voluntarily controlled muscle surrounding the internal sphincter that contributes mainly to squeeze pressure and can be assessed by digital examination and endoanal ultrasound.

A U-shaped sling of the levator ani that wraps the anorectal junction and maintains the anorectal angle, contributing importantly to continence; its division can cause incontinence.

The angulation between the rectal axis and the anal canal created mainly by puborectalis tone; it helps preserve continence and is assessed during defecography.

A small mucosal pocket at the dentate line into which anal glands drain; infection or obstruction of a crypt is believed to be the origin of most cryptoglandular abscesses and fistulas.

A small branched gland whose duct opens into an anal crypt at the dentate line; obstruction and infection of these glands underlie cryptoglandular anorectal suppuration.

An acute anorectal infection arising from obstructed anal glands, presenting as a painful perianal or ischioanal collection that is treated by prompt incision and drainage.

An abnormal epithelialized tract connecting the anal canal or rectum to the perianal skin, usually a sequela of cryptoglandular abscess, classified by its relationship to the sphincter complex.

A clinical guide stating that anterior external fistula openings usually track in a straight radial line to the anal canal, whereas posterior openings usually curve to the posterior midline.

Surgical laying open of an anal fistula tract along its length so it heals by secondary intention; risk of incontinence rises when significant sphincter muscle is divided.

A suture or drain placed through a fistula tract, used either to mark the tract or to slowly cut through sphincter muscle over time to preserve continence in complex fistulas.

A cryptoglandular collection that spreads circumferentially through the deep postanal space to involve both ischioanal fossae, often requiring staged drainage and seton placement.

Division of the internal anal sphincter, usually at the lateral position, to relieve sphincter spasm in chronic anal fissure; it is the main surgical treatment but carries some incontinence risk.

A painful linear tear in the anoderm, typically in the posterior midline, causing sharp pain with defecation; chronic fissures show a sentinel tag or hypertrophied papilla.

Injection of botulinum toxin into the internal anal sphincter to temporarily relax sphincter tone, used as a second-line treatment for chronic anal fissure.

An acutely painful, firm perianal nodule caused by thrombosis within an external hemorrhoid, often treated by excision if seen within the first few days of symptoms.

The network of vascular cushions in the submucosa of the anal canal that helps maintain continence; symptomatic enlargement, bleeding, or prolapse constitutes hemorrhoidal disease.

An office procedure in which a small elastic band is placed at the base of an internal hemorrhoid to cause ischemic fixation and sloughing; it is used for prolapsing internal disease.

Surgical excision of symptomatic hemorrhoidal tissue, usually reserved for large, prolapsed, or mixed internal-external disease that has failed office-based treatments.

A chronic inflammatory tract in the natal cleft, thought to arise from hair entering the skin and forming a foreign-body reaction; it may present as an acute abscess or chronic draining sinus.

An acute collection in the natal cleft complicating pilonidal disease, treated initially by incision and drainage, often followed later by definitive excision or off-midline closure.

Surgical opening of an abscess to release pus and relieve pain; it is the primary treatment for anorectal and pilonidal abscesses, with antibiotics used selectively.

Involuntary loss of liquid or solid stool or gas, resulting from sphincter weakness, nerve injury, or altered stool consistency; evaluation includes endoanal ultrasound and manometry.

A test that measures resting and squeeze pressures and sensory thresholds in the anal canal and rectum, used to assess incontinence, constipation, and Hirschsprung disease.

An imaging technique using an intra-anal probe to delineate sphincter anatomy, identify defects, and guide surgical planning for fistula or incontinence.

Dynamic imaging, usually fluoroscopic or MRI, of the rectum and pelvic floor during defecation, used to evaluate obstructed defecation, rectocele, and intussusception.

Full-thickness protrusion of the rectal wall through the anal verge, distinct from mucosal prolapse; surgical repair is usually required and may be abdominal or perineal.

The spectrum of natal-cleft inflammatory conditions ranging from asymptomatic pits to acute abscess and chronic sinus tracts, most common in young hirsute adults.

The anatomic area overlying the sacrum and coccyx between the buttocks, where pilonidal disease typically arises and where other midline lesions must be differentiated.

The ongoing process by which osteopathic physicians maintain board certification through periodic activities such as continuing education, practice performance, and knowledge assessment.

The framework of ongoing requirements a certified physician must meet to retain board certification, including education, assessment, and practice improvement activities.

A component of certification maintenance in which a physician reviews outcomes or process data from their own practice and documents improvement, often in a structured quality project.

The mandated number of continuing medical education credits a physician must earn over a defined cycle, often including specified hours in relevant specialty or ethics topics.