Proctalgia Fugax

Proctalgia fugax is a common cause of pain in the rectum. Symptoms consistent with proctalgia fugax occur in 13 to 19 percent of the general population.
Proctalgia fugax is underrepresented in the medical literature, and many physicians are unaware of its existence. Lack of familiarity on the part of the physician can result in unnecessary diagnostic evaluation. Contributing to the relative lack of familiarity is the fact that most patients with proctalgia fugax do not seek medical attention because the pain is usually brief and often infrequent. Patients may also be reluctant to disclose the symptoms because they fear potentially painful diagnostic procedures or the possibility of a serious condition

• Anorectal pain is a relatively common symptom first described by the Romans.
• Patients will often delay consulting a healthcare practitioner about this problem due to embarrassment and fear of a sinister diagnosis, tolerating disturbing symptoms for long periods.
• There are two functional anorectal pain syndromes:
• Proctalgia fugax (PF) (fugax=fugitive/fleeting in Greek) and
• Levator ani syndrome (LAS)
• They are both characteristic, benign anorectal-pain syndromes of uncertain aetiology.
• Despite their benign nature, they can cause severe distress to the sufferer. There is even an account of marital disharmony caused by proctalgia fugax.

Aetiology

• They are thought to occur due to spasm of the anal sphincter (PF) or pelvic floor muscles (LAS) but are something of an enigma.
• They may be associated with irritable bowel syndrome. The two affected muscles are anatomically contiguous so the two conditions may co-exist, or be different manifestations of the same underlying dysfunction.
• The diagnosis of these conditions can usually be made on the basis of the symptoms.
• However, more serious diagnoses can present similarly. Thus, it is essential to conduct a thorough clinical assessment to exclude other pathology before offering reassurance.
• May be associated with low-fibre diet and irritable bowel syndrome. More than half of affected patients are aged 30–60 years and prevalence declines after age 45.⁶
• It has been associated with a variety of other pathologies which may have aetiological significance, for example pudendal nerve neuralgia.

Epidemiology

• PF is estimated to affect 8–18% of the population in the developed world, and LAS around 6%.
• LAS seems to affect women more than men.
• It is thought that only 20–30% of sufferers of these conditions consult a healthcare practitioner.

Differential diagnosis

• Irritable bowel syndrome
• Haemorrhoids ± thrombosis
• Anal fissure (usually causes intense localised pain associated with and following defecation) – should be visible on proctoscopy.
• Solitary chronic rectal ulcer
• Rectal carcinoma
• Perirectal abscess or fistula; hydradentis suppuritiva
• Proctitis (especially gonococcal/chlamydial infection)
• Crohn's/Ulcerative colitis.
• Rectal foreign body
• Pruritus ani.
• Diverticular disease
• Rectal prolapse
• Coccygodynia (neuralgic pain around the region of the coccyx)
• Retrorectal cysts
• Condylomata acuminata (anogenital warts)
• Testicular carcinoma
• Prostatitis
• Cystitis
• Psychological cause (some hypothesise that these conditions are psychological rather than physical in origin)
• Alcock's canal syndrome (pudendal neuralgia due to entrapment, may present similarly to PF/be aetiologically relevant)
• Hereditary anal sphincter myopathy
• Bilateral internal iliac artery occlusion

Proctalgia fugax

Presentation

• Symptoms:
• Recurrent episodes of sudden, severe cramping pain localised to the anus or lower rectum.
• Last from seconds to minutes and resolves completely.
• The patient is entirely pain free between the episodes.
• Symptoms often occur at night and may wake the sufferer. Attacks are infrequent (<5>
• Attacks may come in clusters (occurring daily) then abate for long periods.
• Signs:
• PF has no signs and the diagnosis is made on the basis of characteristic symptoms and the absence of signs of other pathology.
• Abdominal and digital rectal examination should constitute the minimum assessment of anal pain.
• Ideally, anoscopy/proctoscopy should be carried out.
• Consider gynae/scrotal examination if relevant.
• Further examination with a sigmoidoscope or colonoscope may be necessary in selected patients where there is suspicion of pathology higher in the colon.
• It is worth checking for signs of anaemia if GI bleeding is suspected.

Management

• Once the diagnosis is made, reassurance is usually sufficient.
• The symptoms are so transient that drug therapy is rarely needed.
• In patients who suffer frequent, severe, prolonged attacks, inhaled salbutamol has been shown to reduce their duration.
• Clonidine and amylnitrate have also been used but no evidence exists for their efficacy.