Proctalgia Fugax

Proctalgia fugax is a functional anorectal pain disorder with brief, severe, episodic pain in the rectum unrelated to defecation.

• Prevalence is 8 to 18% in the general population, with a slight female predominance. Onset is at 30 to 60 years.
• Episodes last seconds to minutes (under 30 minutes), occur infrequently, and resolve spontaneously.
• Proposed mechanism: spasm of the internal anal sphincter or pelvic floor smooth muscle. Pudendal neuropathy is a differential.
• Triggers: stress, anxiety, constipation, menstruation, sexual activity, defecation, anorectal procedures.
• No structural disease is present, and it carries no serious sequelae.

• Sudden severe, cramping or stabbing rectal pain lasting seconds to minutes, often at night waking the patient.
• Pain-free between episodes, with an interval of weeks to months.
• Examination is normal. Pelvic floor tenderness is absent (which distinguishes from levator ani syndrome).
• Red flags for other disease: persistent pain, bleeding, weight loss, change in bowel habit, fever, mass.

• Diagnosis is clinical (Rome IV): recurrent episodes of pain localised to the rectum, lasting seconds to 30 minutes, with no anorectal pain between episodes.
• Examine the anus and rectum, and perform a digital rectal examination to exclude fissure, abscess, thrombosed haemorrhoid, mass, and pelvic floor tenderness.
• Investigations are only needed if red flags: flexible sigmoidoscopy, colonoscopy, MRI pelvis.
• Exclude pudendal neuralgia, proctitis, Crohn disease, prostatitis, coccydynia, and endometriosis.

• Reassurance and education are the mainstay, as the condition is benign.
• Acute episode: sitting in a warm bath, anal massage, or the Valsalva manoeuvre, and deep breathing.
• Inhaled salbutamol 200 micrograms (2 puffs) at onset aborts episodes in about 50 to 60%.
• Topical glyceryl trinitrate 0.2% ointment applied to the anal margin, or nitroglycerin sublingual 0.4 mg.
• Frequent or prolonged episodes: diltiazem 60 mg twice daily or topical diltiazem 2%.
• Clonidine 0.1 mg or botulinum toxin 100 units into the puborectalis or anal sphincter for severe refractory cases.
• Treat constipation with fibre and macrogol, manage stress and anxiety.
• Surgery has no role.