Int J Colorectal Dis (2012) 27:931–937 DOI 10.1007/s00384-012-1415-9 ORIGINAL ARTICLE Critical reappraisal of anorectal function tests in patients with faecal incontinence who have failed conservative treatment T. J. Lam & C. J. J. Mulder & R. J. F. Felt-Bersma Accepted: 20 January 2012 / Published online: 18 February 2012 # The Author(s) 2012. This article is published with open access at Springerlink.com Abstract Objective Anorectal function tests are often performed in patients with faecal incontinence who have failed conserva- tive treatment. This study was aimed to establish the addi- tive value of performing anorectal function tests in these patients in selecting them for surgery. Patients and methods Between 2003 and 2009, all referred patients with faecal incontinence were assessed by a ques- tionnaire, anorectal manometry and anal endosonography. Patients with diarrhea, inflammatory bowel disease, pouches or rectal carcinoma were excluded. Results In total, 218 patients were evaluated. Of these, 107 (49%) patients had no sphincter defects, 71 (33%) had small defects and 40 (18%) had large defects. Anorectal manometry could not differentiate between patients with and without sphincter defects. Patients with sphincter defects were only found to have a significantly shorter sphincter length and reduced rectal capacity compared to patients without sphincter defects. Forty-three patients (20%) had a normal anal pressures ≥40 mmHg. Seventeen patients (8%) had also a dyssynergic pelvic floor both on clinical examination and anorectal manometry. Fifteen patients (7%) had a reduced rectal capacity between 65 and 100 ml. There was no differ- ence in anal pressures or the presence of sphincter defects in these patients compared to patients with a rectal capacity >150 ml. There was no correlation between anorectal manom- etry, endosonography and faecal incontinence severity scores. Conclusion In patients with faecal incontinence who have failed conservative treatment, only anal endosonography can reveal sphincter defects. Anorectal manometry should T. J. Lam (*) : C. J. J. Mulder : R. J. F. Felt-Bersma Department of Gastroenterology and Hepatology, VU University Medical Center, P.O. Box 7057, 1007 MB, Amsterdam, The Netherlands e-mail: tj.lam@vumc.nl be reserved for patients eligible for surgery to exclude those with suspected dyssynergic floor or reduced rectal capacity. Keywords Faecal incontinence . Diagnostic tests . Anorectal manometry . Anal endosonography . Anal sphincter Introduction Faecal incontinence (FI) is a disabling condition with an estimated prevalence of 6% in the adult population [1]. Causes of FI are disruption of the anal sphincters secondary to obstetric or surgical trauma, neurologic impairment related to nervus pudendus damage due to chronic straining during delivery or chronic constipation, neuropathy such as diabetes mellitus and multiple sclerosis, decreased rectal capacity (RC) secondary to inflammatory bowel disease, radiation proctitis or irritable bowel syndrome (IBS), diarrhea, reduced mental awareness and the physical inability to reach toilet facilities. Treatment options for FI are limited. The first step in the management of patients with FI is often dietary modification with fibre and physiotherapy or biofeedback [2–4]. The efficacy of these therapies varies from 50% and 70% for dietary fibre and biofeedback, respectively [5–7]. In patients who are refractory to conservative treatment, surgical inter- vention aimed at correcting a diagnosed sphincter defect, would be the next approach. Other surgical techniques such as sacral nerve stimulation (SNS), gracilis plasty and artificial bowel sphincter creation may be offered to selected patients and are only performed in limited centers [8, 9]. Anal endosonography and MRI are considered as valuable tools for demonstrating the integrity of the anal sphincters and consequently play a key role in helping to select patients for surgical repair [10, 11]. The sensitivity and specificity of anal endosonography reach almost 100% in identifying anal