934 Rectal compliance Fifteen patients (7%) had an RC between 65 and 100 ml. These patients did not differ from patients with an RC >100 or patients with an RC >150 ml with regard to anal pressures and the presence of sphincter defects. There was no difference in RC between patients with normal and (very) low pressures. When analyzing RC parameters for male and female patients separately, the results remained the same. Anal endosonography The frequency and type of sphincter defects are presented in Table 2. Patients without sphincter defects were older, had less previous surgery and had a larger RC in comparison to patients with an anal sphincter defect. Furthermore, patients with large defects tended to have a lower MBP (35 vs. 40 mmHg; P 0 0.09) and a shorter SL (2.8 vs. 3.1 cm; P 0 0.07) compared to patients without sphincter defects. Four patients with large sphincter defects had an RC ≤100 ml. No differences were found in anal manometry findings between patients with small and large defects as well as patients with an ESD and combined ISD and ESD. Patients with atrophy had a lower MBP (34 vs. 39 mmHg; P 0 0.04) and a lower MSP (23 vs. 30 mmHg; P 0 0.001) compared to patients without atrophy. In the group of patients without defects, patients with atrophy had a lower MBP (35 vs. 43 mmHg; P 0 0.01) and a lower MSP (24 vs. 32 mmHg; P 0 0.004) compared to patients without atrophy. Faecal incontinence scores The mean Vaizey score and the Wexner score were 15 (range 6–22) and 13 (range 6–20), respectively. The Vaizey score did not correlate with the MBP, the MSP or the RC. Similar findings were found for the Wexner score. However, when the population was subdivided with respect to the stool consistency, a correlation was found between the Vaizey score and the MBP and MSP in patients with soft stool (r 0 −0.27, P0 0.01 and r 0 −0.23, P0 0.03, respectively). Regarding the Wexner score, a significant correlation was found with the MSP in patients with soft stool (r 0 −0.27, Table 2 Findings of anal endosonography ESD external sphincter defect, ISD internal sphincter defect, not applicable Int J Colorectal Dis (2012) 27:931–937 P0 0.01). No correlation was found between FI scores and sphincter defects. Discussion After therapeutic failure of dietary fibre and physiotherapy, referral and subsequent investigation of patients with FI generally follows. For the detection of anal sphincter defects, anal endosonography (or MRI) is mandatory and considered as the gold standard. Our study has confirmed that anal manometry has no contribution in detecting ano- rectal sphincter defects. Although patients with large defects tended to have lower MBP (P 0 0.09) and shorter SL (P 0 0.07) than patients without sphincter defects, anorectal manometry could not differentiate between patients with and without defects. Other studies have shown comparable results [13, 22]. Anorectal manometry reflects the anal pres- sures; low pressures are caused by anal sphincter defects, pudendal neuropathy or both. A novel anorectal manometry technique, the anal pres- sure vectography has been developed. It evaluates the radial pressures from a quantified vector symmetry index (VSI) that indicates the anatomical integrity of the anal sphincter. A recent study showed that the VSI was as sensitive as anal endosonography in diagnosing an anal sphincter defect [23]. However, the low pressures measured by VSI cannot differ- entiate between internal and external sphincter defects and the position of the catheter in the patient is crucial. In contrast with anal endosonography, the internal and external sphincter can be clearly visualized and the location of the sphincter defects is directly related to other anatomical structures. Furthermore, anal endosonography is less time consuming and easier to perform than vectography. Although VSI can produce interesting data for research purposes, it has no place in the work-up of the patient with FI. Anal endosonography is preferable considering the costs and availability. If anorectal manometry is not useful in the next step of detecting sphincter defects, then what is its contribution in patients who are eligible for surgery? Exclusion of patients with functional abnormalities, such as IBS patients with a small RC or patients with a dyssynergic pelvic floor, seems Patients with no defects (n0107) Patients with small defects (n071) Patients with large defects (n040) Type of sphincter defect ESD (%) ISD (%) Combined ISD and ESD (%) Sphincter atrophy (%) 34 (32%) 66 (93%) 0 5 (7%) 7 (10%) 11 (28%) 0 29 (73%) 4 (10%)