Anal fistula (Clinical)

Definition and Epidemiology

Definition

• Abnormal connection between the epithelium Epithelium The epithelium is a complex of specialized cellular organizations arranged into sheets and lining cavities and covering the surfaces of the body. The cells exhibit polarity, having an apical and a basal pole. Structures important for the epithelial integrity and function involve the basement membrane, the semipermeable sheet on which the cells rest, and interdigitations, as well as cellular junctions. Surface Epithelium: Histology of the anal canal and another body structure (often to the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions) 
• Also called fistula-in-ano Fistula-in-ano Anal fistulas are abnormal communications between the anorectal lumen and another body structure, often to the skin. Anal fistulas often occur due to extension of anal abscesses but are also associated with specific diseases such as crohn’s disease. Anal Fistula

Epidemiology^[1,3,7]

• Incidence Incidence The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from prevalence, which refers to all cases in the population at a given time. Measures of Disease Frequency: 9 per 100,000 adults per year
• Sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria: men > women
• More common between the 3rd and 5th decades of life
• 50% of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with anorectal abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease will eventually develop a fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula.

Etiology and Pathophysiology

Etiology^[1–3]

• Anorectal fistulas most often occur from:
  • An acute anal abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease → ruptures or is drained → epithelialized tract forms that connects the abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease in the anus to the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions (chronic process)
  • Anal abscesses (infected anal crypt glands often with reduced blood flow Blood flow Blood flow refers to the movement of a certain volume of blood through the vasculature over a given unit of time (e.g., mL per minute). Vascular Resistance, Flow, and Mean Arterial Pressure)
• Other causes:
  • Rectal foreign bodies
  • Inflammatory bowel disease (Crohn’s disease)
  • Trauma (obstetric injury)
  • Anal fissures Anal fissures A painful linear tear at the margin of the anus. It appears as a crack or slit in the mucous membrane of the anus and is very painful and difficult to heal. Constipation
  • Malignancy Malignancy Hemothorax
  • Radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma proctitis Proctitis Inflammation of the mucous membrane of the rectum, the distal end of the large intestine. Chronic Granulomatous Disease
  • Infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease ( lymphogranuloma venereum Lymphogranuloma venereum Subacute inflammation of the inguinal lymph glands caused by certain immunotypes of Chlamydia trachomatis. It is a sexually transmitted disease in the U.S. But is more widespread in developing countries. It is distinguished from granuloma venereum, which is caused by calymmatobacterium granulomatis. Chlamydial Infections)

Pathophysiology^[1–3]

• Obstruction of anal glands in the wall of the anal canal → stasis and overgrowth of the bacteria Bacteria Bacteria are prokaryotic single-celled microorganisms that are metabolically active and divide by binary fission. Some of these organisms play a significant role in the pathogenesis of diseases. Bacteriology → anal abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease formation → extension Extension Examination of the Upper Limbs of the abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease into adjacent perirectal spaces → fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula formation
• May also occur secondary to disease states (e.g., Crohn’s disease)
• Fistulas may remain open due to:
  • Foreign body Foreign Body Foreign Body Aspiration
  • Radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma
  • Infection
  • Epithelialization Epithelialization Anal Fistula
  • Neoplasm
  • Distal obstruction
  • Other:
    • Increased flow Flow Blood flows through the heart, arteries, capillaries, and veins in a closed, continuous circuit. Flow is the movement of volume per unit of time. Flow is affected by the pressure gradient and the resistance fluid encounters between 2 points. Vascular resistance is the opposition to flow, which is caused primarily by blood friction against vessel walls. Vascular Resistance, Flow, and Mean Arterial Pressure
    • Steroids Steroids A group of polycyclic compounds closely related biochemically to terpenes. They include cholesterol, numerous hormones, precursors of certain vitamins, bile acids, alcohols (sterols), and certain natural drugs and poisons. Steroids have a common nucleus, a fused, reduced 17-carbon atom ring system, cyclopentanoperhydrophenanthrene. Most steroids also have two methyl groups and an aliphatic side-chain attached to the nucleus. Benign Liver Tumors

Clinical Presentation

History^[1–3]

• Non-healing anal abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease, often associated with purulent drainage or malodorous discharge
• Rectal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways

Physical exam^[1–3]

• Inflamed perianal skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions
• External fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula tract opening may be observed or palpated as an area of induration Induration Dermatologic Examination.
• Associated with a palpable cord-like tract
  • Internal fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula tract opening may be palpated on digital rectal exam ( DRE DRE A physical examination in which the qualified health care worker inserts a lubricated, gloved finger of one hand into the rectum and may use the other hand to press on the lower abdomen or pelvic area to palpate for abnormalities in the lower rectum, and nearby organs or tissues. The method is commonly used to check the lower rectum, the prostate gland in men, and the uterus and ovaries in women. Prostate Cancer Screening); however, anoscope or further imaging may be needed to identify the fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula tract.

Diagnosis and Management

Diagnosis^[1,3,4,7]

• Based on history, physical exam, and radiology findings
• Evaluation should include:
  • Baseline anal sphincter function
  • Relevant details about anorectal operations, family history Family History Adult Health Maintenance of inflammatory bowel disease (IBD), obstetric history Obstetric History Prenatal Care, and associated GI, genitourinary, or gynecologic pathology
  • Associated disease or diseases
  • Abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease and fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula location
  • Checking for secondary cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis
• Identification Identification Defense Mechanisms:
  • Internal opening on exam of the rectal area
  • Goodsall rule
    • Fistulas originating anterior to a transverse line through the anus will have a straight course and exit anteriorly.
    • Fistulas originating posterior to the transverse line will begin in the midline and have a curved tract.
  • Exception to the Goodsall rule: fistulas > 3 cm from the anal verge
  • Fistulous tract:
    • Can be detected by probing or fistulography under anesthesia Anesthesia A state characterized by loss of feeling or sensation. This depression of nerve function is usually the result of pharmacologic action and is induced to allow performance of surgery or other painful procedures. Anesthesiology: History and Basic Concepts
    • A fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula probe Probe A device placed on the patient’s body to visualize a target Ultrasound (Sonography) must be used with care to prevent penetration Penetration X-rays of the fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula wall.
    • Rectal involvement requires the use of a sigmoidoscope.
• Preferred imaging:
  • Endoanal ultrasonography:
    • Defines complex fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula tracts
    • Can be used with hydrogen peroxide Hydrogen peroxide A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials. Myeloperoxidase Deficiency injection
    • Operator-dependent, but generally correlates with intraoperative exam in 90%–94% of cases
  • MRI of the pelvis Pelvis The pelvis consists of the bony pelvic girdle, the muscular and ligamentous pelvic floor, and the pelvic cavity, which contains viscera, vessels, and multiple nerves and muscles. The pelvic girdle, composed of 2 “hip” bones and the sacrum, is a ring-like bony structure of the axial skeleton that links the vertebral column with the lower extremities. Pelvis: Anatomy:
    • Correlates with correct anatomy 90% of the time
    • More expensive than ultrasonography, but less operator-dependent

Types of fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula^[1,3,6]

• Parks classification:
  • Intersphincteric Intersphincteric Perianal and Perirectal Abscess (most common):
    • Fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula between the external and internal sphincters, terminating in the perianal skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions
    • Spares the external sphincter
  • Transsphincteric: The track is through the external sphincter into the ischiorectal Ischiorectal Perianal and Perirectal Abscess fossa.
  • Suprasphincteric: The fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula starts at the anal crypt, penetrates the internal anal sphincter Internal anal sphincter Rectum and Anal Canal: Anatomy, and goes superiorly above the intersphincteric Intersphincteric Perianal and Perirectal Abscess plane.
  • Extrasphincteric:
    • High in the anal canal and tracks through the sphincter complex, going lateral to the sphincters before ending in the skin Skin The skin, also referred to as the integumentary system, is the largest organ of the body. The skin is primarily composed of the epidermis (outer layer) and dermis (deep layer). The epidermis is primarily composed of keratinocytes that undergo rapid turnover, while the dermis contains dense layers of connective tissue. Skin: Structure and Functions
    • Results from trauma, Crohn disease, or foreign bodies
• Not included in the Parks classification: superficial or submucosal (does not involve the sphincter muscles)

Management

General principles:^[4–7]

• The only definitive treatment for anal fistulas is surgery.
• Goals of surgical treatment:
  • Eradicate sepsis Sepsis Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock. Sepsis and Septic Shock
  • Promote healing of fistulous tract
  • Preserve sphincters and continence
• Management includes controlling the infection (e.g., promptly draining the abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease if present) prior to definitive treatment.
• For the purposes of choosing appropriate treatment, fistulas are defined as simple or complex:
  • Simple fistulas are intersphincteric Intersphincteric Perianal and Perirectal Abscess or low transsphincteric, involving < 30% of the external sphincter without any complicating factors
  • Complex fistulas:
    • Higher fistulas with more muscle involvement
    • Anterior fistulas in females
    • Recurrent or branching fistulas
    • Fistulas in the setting of preexisting incontinence, inflammatory bowel disease, or radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma

Surgical techniques:^[4–7]

• Fistulotomy Fistulotomy Anal Fistula for simple fistulas:
  • Complete transection of the tissue between the fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula tract and anoderm
  • Procedure of choice for simple fistulas
  • Success rate up to 100%
  • Incontinence rates < 10%
• Procedures for complex fistulas (the choice will depend on the specific patient situation and surgeon preference):
  • Fistulotomy Fistulotomy Anal Fistula is generally not recommended in patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with complex fistulas.
    • Associated with postoperative incontinence in up to 40% of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship
    • Additionally, fistulotomy Fistulotomy Anal Fistula is best avoided in those who have had previous anorectal surgery due to increased postoperative anal sphincter dysfunction.
  • Draining seton:
    • Often used as a bridge for a more definitive repair in complex fistulas
    • Controls perianal sepsis Sepsis Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by hypotension despite adequate fluid infusion, it is called septic shock. Sepsis and Septic Shock and allows a fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula tract to mature
    • Usually constructed from a silastic vessel loop pulled through the tract and tied loosely to itself with a suture
  • Cutting seton:
    • Seton is secured tightly in the fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula with intentional pressure on the tract.
    • Seton cuts gradually through the muscle, allowing buildup of fibrotic tract.
    • Healing takes 12–16 weeks.
    • Used selectively in complex fistulas owing to variable Variable Variables represent information about something that can change. The design of the measurement scales, or of the methods for obtaining information, will determine the data gathered and the characteristics of that data. As a result, a variable can be qualitative or quantitative, and may be further classified into subgroups. Types of Variables functional outcomes (incontinence rate of up to 67% depending on the type of fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula tract)
  • Endorectal advancement flap (ERAF):
    • Involves fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula tract curettage Curettage A scraping, usually of the interior of a cavity or tract, for removal of new growth or other abnormal tissue, or to obtain material for tissue diagnosis. It is performed with a curet (curette), a spoon-shaped instrument designed for that purpose. Benign Bone Tumors, closure of the external opening, and mobilization of a partial thickness flap consisting of rectal mucosa, submucosa, and some muscle fibers to cover the defect
    • Success rates 65%–93%
    • A 2nd attempt can be performed with healing rates of 69%.
    • Effects on continence are minimal.
    • Factors that increase failure: history of Crohn’s disease, active proctitis Proctitis Inflammation of the mucous membrane of the rectum, the distal end of the large intestine. Chronic Granulomatous Disease, smoking Smoking Willful or deliberate act of inhaling and exhaling smoke from burning substances or agents held by hand. Interstitial Lung Diseases, malignancy Malignancy Hemothorax, obesity Obesity Obesity is a condition associated with excess body weight, specifically with the deposition of excessive adipose tissue. Obesity is considered a global epidemic. Major influences come from the western diet and sedentary lifestyles, but the exact mechanisms likely include a mixture of genetic and environmental factors. Obesity
  • Dermal advancement flap:
    • An alternative to ERAF in technically challenging cases
    • An advancement flap is moved from the anal margin Anal margin Anal Cancer into the anal canal.
    • 70%–80% success rate
  • Ligation Ligation Application of a ligature to tie a vessel or strangulate a part. Esophageal Atresia and Tracheoesophageal Fistula of intersphincteric Intersphincteric Perianal and Perirectal Abscess fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula tract (LIFT):
    • Identification Identification Defense Mechanisms, ligation Ligation Application of a ligature to tie a vessel or strangulate a part. Esophageal Atresia and Tracheoesophageal Fistula, and division of the transsphincteric tract
    • Healing rates reported from 40%–95%
    • Complications are minimal.
    • A 2nd attempt has a reported success rate of 54%.
    • Acceptable approach for patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with Crohn’s disease
  • Emerging minimally invasive treatments (with reasonable healing rate but still unknown long-term healing and recurrence rate):
    • Laser: causes scarring Scarring Inflammation and shrinking of tissue along the fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula
    • Video-assisted anal fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula treatment (VAAFT): destroys fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula tract under direct visualization
  • Stem cell injection into fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula tract: an option for refractory fistulas in Crohn’s disease
• The following are considered relatively ineffective treatments, in general because of poor healing:^[7]
  • Fibrin Fibrin A protein derived from fibrinogen in the presence of thrombin, which forms part of the blood clot. Rapidly Progressive Glomerulonephritis sealants:
    • Filling fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula tract with fibrin Fibrin A protein derived from fibrinogen in the presence of thrombin, which forms part of the blood clot. Rapidly Progressive Glomerulonephritis glue
    • Provides scaffold for native tissue ingrowth
    • Primary healing rate of 30%–60%, with long-term success dropping to 14% at 16 months
  • Fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula plug:
    • Placing bioprosthetic plug within the fistula Fistula Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body. Anal Fistula tract
    • Initial healing rates of 85%, but with longer follow-up can be as low as 24%

Antibiotics:^[7]

• Use selectively in cases of cellulitis Cellulitis Cellulitis is a common infection caused by bacteria that affects the dermis and subcutaneous tissue of the skin. It is frequently caused by Staphylococcus aureus and Streptococcus pyogenes. The skin infection presents as an erythematous and edematous area with warmth and tenderness. Cellulitis or systemic infection or in immunosuppressed patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship.
• In general, antibiotics for anorectal abscess Abscess Accumulation of purulent material in tissues, organs, or circumscribed spaces, usually associated with signs of infection. Chronic Granulomatous Disease have not improved healing or reduced recurrence.
• Obtain cultures in case of recurrent infections Recurrent infections Common Variable Immunodeficiency (CVID) or nonhealing wounds.

Mnemonic

Why fistulas stay open: “FRIENDS”

• Foreign body
• Radiation
• Infection
• Epithelialization
• Neoplasm
• Distal obstruction
• Steroids

Differential Diagnosis

• Anal carcinoma: neoplastic disease in which cancer cells form and grow in the anus. Symptoms include bleeding from the anus, anal pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, anal mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast, or itching. Risk factors include older age, infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease including human papillomavirus Human papillomavirus Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomavirus (HPV) ( HPV HPV Human papillomavirus (HPV) is a nonenveloped, circular, double-stranded DNA virus belonging to the Papillomaviridae family. Humans are the only reservoir, and transmission occurs through close skin-to-skin or sexual contact. Human papillomaviruses infect basal epithelial cells and can affect cell-regulatory proteins to result in cell proliferation. Papillomavirus (HPV)), multiple sexual partners, and anal sex Sex The totality of characteristics of reproductive structure, functions, phenotype, and genotype, differentiating the male from the female organism. Gender Dysphoria. Anal carcinoma is diagnosed by biopsy Biopsy Removal and pathologic examination of specimens from the living body. Ewing Sarcoma. Treatment can include surgery, radiation Radiation Emission or propagation of acoustic waves (sound), electromagnetic energy waves (such as light; radio waves; gamma rays; or x-rays), or a stream of subatomic particles (such as electrons; neutrons; protons; or alpha particles). Osteosarcoma, or chemotherapy Chemotherapy Osteosarcoma. In a chronic or atypical anal fissure Fissure A crack or split that extends into the dermis Generalized and Localized Rashes, anal carcinoma needs to be ruled out.
• Hemorrhoids Hemorrhoids Hemorrhoids are normal vascular cushions in the anal canal composed of dilated vascular tissue, smooth muscle, and connective tissue. They do not cause issues unless they are enlarged, inflamed, thrombosed, or prolapsed. Patients often present with rectal bleeding of bright red blood, or they may have pain, perianal pruritus, or a palpable mass. Hemorrhoids: enlargement of anal cushions (submucosal vessels) at the distal rectum Rectum The rectum and anal canal are the most terminal parts of the lower GI tract/large intestine that form a functional unit and control defecation. Fecal continence is maintained by several important anatomic structures including rectal folds, anal valves, the sling-like puborectalis muscle, and internal and external anal sphincters. Rectum and Anal Canal: Anatomy. Depending on the location of the veins Veins Veins are tubular collections of cells, which transport deoxygenated blood and waste from the capillary beds back to the heart. Veins are classified into 3 types: small veins/venules, medium veins, and large veins. Each type contains 3 primary layers: tunica intima, tunica media, and tunica adventitia. Veins: Histology, hemorrhoids Hemorrhoids Hemorrhoids are normal vascular cushions in the anal canal composed of dilated vascular tissue, smooth muscle, and connective tissue. They do not cause issues unless they are enlarged, inflamed, thrombosed, or prolapsed. Patients often present with rectal bleeding of bright red blood, or they may have pain, perianal pruritus, or a palpable mass. Hemorrhoids can be internal or external. External hemorrhoids Hemorrhoids Hemorrhoids are normal vascular cushions in the anal canal composed of dilated vascular tissue, smooth muscle, and connective tissue. They do not cause issues unless they are enlarged, inflamed, thrombosed, or prolapsed. Patients often present with rectal bleeding of bright red blood, or they may have pain, perianal pruritus, or a palpable mass. Hemorrhoids are painful, but internal hemorrhoids Hemorrhoids Hemorrhoids are normal vascular cushions in the anal canal composed of dilated vascular tissue, smooth muscle, and connective tissue. They do not cause issues unless they are enlarged, inflamed, thrombosed, or prolapsed. Patients often present with rectal bleeding of bright red blood, or they may have pain, perianal pruritus, or a palpable mass. Hemorrhoids are painless; both can bleed and appear as a soft rectal mass Mass Three-dimensional lesion that occupies a space within the breast Imaging of the Breast on exam. Commonly caused by constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation, and diagnosed on exam. Treatment includes stool softeners, topical hydrocortisone Hydrocortisone The main glucocorticoid secreted by the adrenal cortex. Its synthetic counterpart is used, either as an injection or topically, in the treatment of inflammation, allergy, collagen diseases, asthma, adrenocortical deficiency, shock, and some neoplastic conditions. Immunosuppressants, and sitz baths. For recurrent cases, rubber band ligation Band ligation Mallory-Weiss Syndrome (Mallory-Weiss Tear) or surgical removal is indicated.
• Perianal ulcerations: erosions Erosions Corneal Abrasions, Erosion, and Ulcers in the perianal mucosa. Occur secondary to inflammatory bowel disease, most notably Crohn’s disease, infections Infections Invasion of the host organism by microorganisms or their toxins or by parasites that can cause pathological conditions or diseases. Chronic Granulomatous Disease, and cancer. Symptoms include pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways, bleeding, and erosions Erosions Corneal Abrasions, Erosion, and Ulcers in the lining of the mucosa. Treatment is aimed at the causative disease. Differentiated from anal fissures Anal fissures A painful linear tear at the margin of the anus. It appears as a crack or slit in the mucous membrane of the anus and is very painful and difficult to heal. Constipation on physical exam by deeper erosions Erosions Corneal Abrasions, Erosion, and Ulcers in mucosa and evidence of other causative disease.
• Anal fissure Fissure A crack or split that extends into the dermis Generalized and Localized Rashes: a painful superficial tear of the epithelial lining (anoderm) of the anal canal. Anal fissures Anal fissures A painful linear tear at the margin of the anus. It appears as a crack or slit in the mucous membrane of the anus and is very painful and difficult to heal. Constipation most often occur secondary to local trauma or irritation from constipation Constipation Constipation is common and may be due to a variety of causes. Constipation is generally defined as bowel movement frequency < 3 times per week. Patients who are constipated often strain to pass hard stools. The condition is classified as primary (also known as idiopathic or functional constipation) or secondary, and as acute or chronic. Constipation, diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea, anal intercourse Anal intercourse Hemorrhoids, or perineal lacerations during childbirth. Treatment is generally conservative, including stool softeners, bulking agents, sitz baths, and/or topical vasodilators Vasodilators Drugs used to cause dilation of the blood vessels. Thromboangiitis Obliterans (Buerger’s Disease).