Chapter 36: Anorectal disorders

INTRODUCTION

Anorectal problems are common in family practice and tend to cause anxiety in the patient that is often related to the fear of cancer. This fear may be well founded for many instances of rectal bleeding and lumps. It is important to keep in mind the association between haemorrhoids and large bowel cancer.

Anorectal problems include:

• pain

• lumps

• discharge

• bleeding

• pruritus

Common anorectal conditions are illustrated in FIGURE 36.1.

The patient may complain that defecation is painful or almost impossible because of anorectal pain.

Causes

Pain without swelling:

• anal fissure

• anal herpes

• ulcerative proctitis

• proctalgia fugax

• solitary rectal ulcer

• tenesmus

Painful swelling:

• perianal haematoma

• strangulated internal haemorrhoids

• abscess: perianal, ischiorectal

• pilonidal sinus

• fistula-in-ano (intermittent)

• anal carcinoma

Anal fissure

Anal fissures cause pain on defecation and usually develop after a period of constipation (may be a brief period) and tenesmus. Other associations are childbirth and opioid analgesics.¹ Sometimes the pain can be excruciating, persisting for hours and radiating down the back of both legs. Anal fissures, especially if chronic, can cause minor anorectal bleeding (bright blood) noted as spotting on the toilet paper.

Examination

On inspection the anal fissure is usually seen in the anal margin, situated in the midline posteriorly (6 o’clock)—90% of fissures. The fissure appears as an elliptical ulcer involving the lower third of the anus from the dentate line to the anal verge (see FIG. 36.2).¹

Digital examination and sigmoidoscopy are difficult because of painful anal sphincter spasm. If there are multiple fissures, Crohn disease should be suspected. These fissures look different, being indurated, oedematous and bluish in colour.

In chronic anal fissures a sentinel pile is common and in long-standing cases, a subcutaneous fistula is seen at the anal margin, with fibrosis and anal stenosis.¹

Treatment

The aim is to disrupt the cycle of anal sphincter spasm, ...