80 T_h e anus and anal canal

ANAL FISSURE Definition An anal fissure (synonym: fissure- in - ano ) is a longitudinal ulcer in the...

ANAL INTRAEPITHELIAL NEOPLASIA AIN is a multifocal virally induced dysplasia of the perianal or ...

ANATOMY AND PHYSIOLOGY OF THE ANAL CANAL Surgical anatomy The anal canal starts at the level wher...

ANORECTAL ABSCESSES Aetiology Acute sepsis in the region of the anus is common, more in men than...

Advancement flaps When the sphincter complex is not too indurated and adequate intra-anal access c...

Aetiology The cause of an anal fissure, and particularly the reason why the posterior midline is ...

Anal advancement flap An anal advancement flap to cover the anal fissure should be considered in tho...

Anal canal anatomy The anus is 3–4 /uni00A0 cm long in adults, being longer in the adult male tha...

Anal sphincter surgery In situations where conservative treatment has failed, and where a discret...

Biological agents The functional consequences of fistulotomy have led to a search for agents that...

CONDYLOMATA ACUMINATA (ANAL WARTS) There is increasing evidence that sexually transmitted infecti...

CONGENITAL ABNORMALITIES Early in embryonic life there is a common chamber – the cloaca – into wh...

Classification The most widely used classification of anal fistulae (Parks’) is based on anal gland ...

Clinical assessment A full medical (including obstetric, gastrointestinal, anal surgical and cont...

Clinical features Although superficial, acute anal fissures are characterised by severe anal pain d...

Diagnosis and management A high index of suspicion and targeted biopsy yields the diag nosis, wh...

Differential diagnosis The only conditions with which an anorectal abscess is likely to be confus...

Digital examination with the index finger With an adequately lubricated index finger, the soft tiss...

EXAMINATION OF THE ANUS Careful clinical examination will be diagnostic in the vast majority of ...

Endometriosis Endometriosis of the rectovaginal septum may present as a stricture. There is usua...

External haemorrhoids A thrombosed external haemorrhoid relates anatomically to the veins of the...

FISTULA- IN-ANO Aetiology A fistula- in - ano , or anal fistula, is a chronic abnormal commu nicati...

FURTHER READING Chu CS, Pfister DG. Opportunities and challenges: human papillomavirus and cancer....

Fissurectomy Surgical excision of a fissure involves excising of the fibrotic edge, curettage of ...

HAEMORRHOIDS Haemorrhoids are symptomatic enlargements of the internal haemorrhoidal venous plex...

HIDRADENITIS SUPPURATIVA HA is a chronic suppurative condition of apocrine gland- bearing skin f...

Hypertrophied anal papilla Anal papillae occur at the dentate line and are remnants of the ectode...

INCONTINENCE Aetiology Continence is dependent upon the structural and functional integrity of b...

Imperforate anus Imperforate anus (strictly , it should be anal ‘agenesis’ or ‘atre sia’) has his...

Injectable biomaterials Injectable biomaterials to add bulk to the anal canal and thereby augment...

Inspection The buttocks are gently parted to allow inspection of the anus and perineum: the pres...

Introduction No content extracted automatically.

Investigations Anorectal physiology studies provide objective assessment of the anorectal functi...

Inflammatory bowel disease Stricture of the anorectum may complicate Crohn’s disease and, in this...

Lateral anal sphincterotomy In this operation, the internal sphincter is divided away from - the ...

Learning objectives To understand: The anatomy and physiology of the anus and anal • canal with...

Lymphatic drainage Lymph from the upper half of the anal canal flows upwards to drain into the m...

MALIGNANT TUMOURS Malignant lesions of the anus and anal canal Anal malignancy is rare and accoun...

Management Most patients with incontinence can be managed conserva - tively with dietary advice, ...

NON-MALIGNANT STRICTURES: ANAL STENOSIS Anal stenosis is a rare but serious complication of anor...

Operations to augment the anal sphincters If the degree of sphincter disruption or weakness is ...

Operations Indications The indications for haemorrhoidectomy include: /uni25CF third- and fourth-...

Operative measures Anal sphincter dilatation has been used to reduce sphincter tone; however, thi...

Other anal malignancies Adenocarcinoma within the anal canal is usually an extension of a distal ...

Other techniques Video-assisted anal fistula treatment (V AAFT) involves the introduction of a ri...

PHYSIOLOGICAL ASPECTS OF THE ANAL SPHINCTERS AND PEL VIC FLOOR Anal continence and defecation ar...

PRURITUS ANI This is intractable itching around the anus, a common and embarrassing condition. Us...

Pathology Occlusion of gland ducts leads to bacterial proliferation, gland rupture and the spread...

Pilonidal sinus The term pilonidal sinus describes a condition found in the natal cleft overlying...

Postanal dermoid The space in front of the lower part of the sacrum and coccyx may be occupied ...

Postoperative care In many countries, haemorrhoidectomy is performed on a day-case basis. The pat...

Postoperative complications Postoperative complications may be early or late. Early complications...

Presentation A perianal abscess, confined by the terminal extensions of the longitudinal muscle, i...

Principles of fistula surgery The aim of surgery is to keep the patient continent and comfortable...

Proctalgia fugax This problem is characterised by attacks of severe pain arising in the rectum, ...

Proctoscopy Proctoscopy , performed with the patient in the same position, allows a detailed insp...

Rectal examination The finger encounters a sharply defined shelf-like interruption of the lumen. I...

Sigmoidoscopy Although sigmoidoscopy is strictly an examination of the rectum, it should always ...

Special investigations A successful outcome after fistula surgery requires careful assessment of ...

The epithelium and subepithelial structures The pink columnar epithelium lining the rectum extend...

Treatment of complications Strangulation and thrombosis are relatively uncommon. The patient pres...

Treatment After confirmation of the diagnosis and exclusion of secondary causes of anal ulcerati...

Venous drainage The anal veins are distributed in a similar fashion to the arterial supply . The ...

coccygea) A dimple in the skin beneath the tip of the coccyx, sometimes amounting to a short bli...