oPatientPlus articles are written by UK doctors and are based on research evidence, UK and European Guidelines. They are designed for health professionals to use, so you may find the language more technical than the condition leaflets.
Synonyms: functional anorectal pain, chronic proctalgia, pyriformis syndrome, pelvic tension myalgia, levator ani syndrome
Functional anorectal pain occurs in the absence of any clinical abnormality. It's 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, defined by the Rome III criteria (2006):
- Proctalgia fugax (PF) (fugax = fugitive/fleeting in Latin)
- 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.
- They are thought to occur due to spasm of the anal sphincter (in PF) or pelvic floor muscles (in LAS) but are something of an enigma.
- It is important to elicit a precise history of defecation.
- They may be associated with irritable bowel syndrome (IBS).
- 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.
- A history of anxiety or depression is often associated and this should be evaluated.
- They have been associated with a variety of other pathologies which may have aetiological significance; for example, pudendal nerve neuralgia.
- Proctalgia fugax (PF) is estimated to affect 8-18% of the population in the developed world, and levator ani syndrome (LAS) around 6%.
- LAS seems to affect women more than men whereas PF seems to affect both sexes equally.
- It is thought that only 20-30% of those who experience these conditions consult a healthcare practitioner.
- 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.
- Colorectal cancer.
- Perirectal abscess or fistula; hidradenitis suppurativa.
- Proctitis (especially gonococcal/chlamydial infection).
- Crohn's disease/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 tumours.
- 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.
- Endoscopy (flexible rectosigmoidoscopy or colonoscopy) should be considered in patients with chronic anorectal pain.
- If this is normal and there is tenderness of the puborectalis muscle then other investigations such as anorectal manometry, balloon expulsion test and MRI-Defecography should be considered.
- Depending on the level of clinical uncertainty, other useful investigations can be FBC, pelvic ultrasound and anorectal endosonography.
Intermittent chronic anal pain syndrome: Proctalgia fugax
- Recurrent episodes of sudden, severe cramping pain localised to the anus or lower rectum.
- Last from seconds to minutes and resolve completely.
- The patient is entirely pain-free between the episodes.
- Symptoms often occur at night and may wake the person who has the condition. Attacks are infrequent (<5 times yearly in 51% of patients).
- Attacks may come in clusters (occurring daily) then abate for long periods.
- 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 gynaecological/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 gastrointestinal bleeding is suspected.
- Once the diagnosis is made, reassurance is usually sufficient.
- The symptoms are so transient that drug therapy is rarely needed.
- In patients who experience frequent, severe, prolonged attacks, inhaled salbutamol has been shown to reduce their duration.
- Most other treatments (such as oral diltiazem, topical glyceryl nitrate and nerve blocks) act by relaxing the anal sphincter spasm but are not supported by randomised controlled trials.
- Co-existent psychological issues should be addressed with behavioural and/or pharmacological therapies.
Chronic anal pain syndrome: Levator ani syndrome
- Vague, aching or pressure sensation high in the rectum often worsened by sitting and relieved by walking.
- Pain tends to be constant or recur regularly and to last >20mins.
- Lasts from hours to days.
- To satisfy diagnostic criteria the symptoms must be present for three months with symptom onset at least six months prior to diagnosis.
- Other causes of similar pain (see 'Differential diagnosis', above) must have been excluded.
- In LAS, posterior traction on the puborectalis reveals tight levator ani muscles and tenderness or pain. (This differentiates between LAS and Unspecified Functional Anorectal Pain).
- Tenderness may be predominantly left-sided and massage of the puborectalis muscle may elicit the characteristic discomfort.
- The recently-published Guidelines on Chronic Pelvic Pain (European Association of Urology) suggest (in decreasing robustness of clinical evidence) :
- Biofeedback treatment
- Botulinum toxin A and electrogalvanic stimulation
- Percutaneous tibial nerve stimuation
- Sacral neurostimulation
- Inhaled salbutamol
- If all functional tests are normal, consider referral to a specialist pain management unit.
- When examining the anogenital area ensure that the patient is fully informed about what to expect and the reasons why the examination is necessary.
- An appropriate chaperone should be offered and be in attendance for intimate examinations.
- Document the presence of a chaperone and their identity along with the examination findings.
- Ensure patient privacy and dignity, and discontinue the examination if at any time you or the patient are unhappy or uncomfortable with the situation.
- Do not assume that because you are the same sex as the patient, a chaperone isn't needed.
- For further information, see separate article Rectal Examination.
Further reading & references
- Atkin GK, Suliman A, Vaizey CJ; Patient characteristics and treatment outcome in functional anorectal pain. Dis Colon Rectum. 2011 Jul;54(7):870-5. doi: 10.1007/DCR.0b013e318217586f.
- Proctalgia Fugax, A pain in the butt; Gihealth.com
- Rome III Diagnostic Criteria for Functional Gastrointestinal Disorders
- Mazza L, Formento E, Fonda G; Anorectal and perineal pain: new pathophysiological hypothesis. Tech Coloproctol. 2004 Aug;8(2):77-83.
- Guidelines on chronic pelvic pain; European Association of Urology (2014)
- Takano M; Proctalgia fugax: caused by pudendal neuropathy? Dis Colon Rectum. 2005 Jan;48(1):114-20.
- Bharucha AE, Trabuco E; Functional and chronic anorectal and pelvic pain disorders. Gastroenterol Clin North Am. 2008 Sep;37(3):685-96, ix. doi: 10.1016/j.gtc.2008.06.002.
- de Parades V, Etienney I, Bauer P, et al; Proctalgia fugax: demographic and clinical characteristics. What every doctor should know from a prospective study of 54 patients. Dis Colon Rectum. 2007 Jun;50(6):893-8.
- Whitehead WE, Wald A, Diamant NE, et al; Functional disorders of the anus and rectum. Gut. 1999 Sep;45 Suppl 2:II55-9.
- Manavi K, McMillan A, Young H; The prevalence of rectal chlamydial infection amongst men who have sex with men attending the genitourinary medicine clinic in Edinburgh. Int J STD AIDS. 2004 Mar;15(3):162-4.
- Singer MA, Cintron JR, Martz JE, et al; Retrorectal cyst: a rare tumor frequently misdiagnosed. J Am Coll Surg. 2003 Jun;196(6):880-6.
- de la Portilla F, Borrero JJ, Rafel E; Hereditary vacuolar internal anal sphincter myopathy causing proctalgia fugax and constipation: a new case contribution. Eur J Gastroenterol Hepatol. 2005 Mar;17(3):359-61.
- Pfenninger JL, Zainea GG; Common anorectal conditions: Part I. Symptoms and complaints. Am Fam Physician. 2001 Jun 15;63(12):2391-8.
- Jeyarajah S, Purkayastha S; Proctalgia fugax. CMAJ. 2013 Mar 19;185(5):417. doi: 10.1503/cmaj.101613. Epub 2012 Nov 26.
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Dr Richard Draper
Dr Nick Imm
Dr Helen Huins