Patient characteristics and treatment outcome in functional anorectal pain

Functional anorectal pain occurs in the absence of any clinical abnormality. It is common and disabling; it has previously been reported in only a few studies involving small patient numbers.

This study aimed to report the clinical characteristics and treatment outcomes for patients with functional anorectal pain.

Patient demographics, clinical history, and tests results for all referrals for anorectal physiological testing between 1997 and 2009 were prospectively recorded. For patients with functional anorectal pain, further information was gained from clinical notes.

Clinical history, anorectal physiology, and radiological imaging data were recorded for all patients; treatment outcome was noted for patients treated and followed up at the present unit.

One hundred seventy patients, 99 female, with a median age of 48 years (range, 18-86), were studied. Patients were classified as having chronic proctalgia (pain duration ≥20 min, 158 patients) or proctalgia fugax (pain duration <20 min, 12 patients). The pain was most commonly located in the anal canal (90%) and aggravated by defecation or sitting (66%). A third of patients had a history of psychological disturbance. Internal anal sphincter thickness correlated with resting anal pressures. Patients with proctalgia fugax had a higher internal anal sphincter thickness and resting pressure than patients with chronic proctalgia, whereas patients with a family history of similar symptoms were more likely to have proctalgia fugax and higher resting pressures and internal anal sphincter thickness compared with those without a family history of these symptoms. Patients referred for treatment underwent a range of interventions including biofeedback (29 patients, 17 improved), tricyclic antidepressants (26 patients, 10 improved), Botox injection (9 patients, 5 improved), and sacral nerve stimulation (3 patients, 2 improved). Biofeedback had the greatest treatment effect, especially in patients with defecatory dysfunction.

Biofeedback is beneficial in the subset of patients with functional anorectal pain and difficulty with defecation. Tricyclic antidepressants, Botox, and sacral nerve stimulation may also have a role.