Anorectal manometry assessment of sphincter relaxation after local-regional anesthesia with posterior perineal block.

INTRODUCTION: Since the 1970s, in the USA, we witnessed a progressive increase of one-day surgical procedures. This attitude soon gained ground in Europe as well. In proctology, this kind of clinical approach has always been limited by the acute sensitivity of the anal- perineal area and by difficulties in attaining a complete sphincter relaxation with local anesthesia. Posterior perineal block seems to be associated with both a good pain control and an effective sphincter relaxation. MATERIAL AND METHODS: Between January 2017 and January 2018, we enrolled in our study 33 patients suffering from hemorrhoidal disease. They were all subjected to posterior perineal block. We measured anal resting pressure and squeeze pressure before and after anesthesia. Measurements where taken 5 minutes before and 15 minutes after the administration of local. RESULTS: We registered an average decrease of 39,2% of resting pressure and of 45,4% of squeeze pressure. CONCLUSIONS: We may state that perineal posterior block, while reducing striated muscle contractile activity, also causes a relevant reduction of anal basal tone. During surgical procedures done under regional anesthesia, we experienced a good sphincter relaxation, which was comparable, if not equal, to that induced by general anesthesia. In fact, 10 to 15 minutes after performing the block you could observe the elevation of the inferior margin of the exterior sphincter and the concomitant descent of the inferior margin of the internal sphincter (coaxial dislocation). KEY WORDS: Anorectal manometry, Anesthesia, Local-regional, Perineal block.

Assessment of brain activity during voluntary anal sphincter contraction: Comparative study in women with and without fecal incontinence.

BACKGROUND: Voluntary anal sphincter function is driven by an extended network of brain structures, most of which are still unknown. Disturbances in this function may cause fecal incontinence. The aim of this study was to characterize the cerebral areas involved in voluntary contraction of the anorectal sphincter in healthy women and in a group of patients with fecal incontinence by using a standardized functional magnetic resonance imaging (fMRI) protocol. METHODS: This comparative study included 12 healthy women (mean age 53.17 ± 4.93 years) and 12 women with fecal incontinence (56.25 ± 6.94 years). An MRI-compatible anal manometer was used to register voluntary external anal sphincter contraction. During brain fMRI imaging, participants were cued to perform 10-s series of self-paced anal sphincter contractions at an approximate rate of 1 Hz. Brain structures linked to anal sphincter contractions were mapped and the findings were compared between the 2 study groups. KEY RESULTS: There were no differences in the evoked brain activity between the 2 groups. In healthy women, group fMRI analysis revealed significant activations in medial primary motor cortices, supplementary motor area, bilateral putamen, and cerebellum, as well as in the supramarginal gyrus and visual areas. In patients with fecal incontinence, the activation pattern involved similar regions without significant differences with healthy women. CONCLUSIONS & INFERENCES: This brain fMRI-anorectal protocol was able to map the brain regions linked to voluntary anal sphincter function in healthy and women with fecal incontinence.

Surgeons' assessment of internal anal sphincter nerve supply during TaTME - inbetween expectations and reality.

BACKGROUND: Intraoperative identification of nerve fibers heading from the inferior rectal plexus (IRP) to the internal anal sphincter (IAS) is challenging. The transanal total mesorectal excision (TaTME) is said to better preserve pelvic autonomic nerves. The aim of this study was to investigate the nerve identification rates during TaTME by transanal visual and electrophysiological assessment. MATERIAL AND METHODS: A total of 52 patients underwent TaTME for malignant conditions. The IRP with its posterior branches to the IAS and the pelvic splanchnic nerves (PSN) were visually assessed in 20 patients (v-TaTME). Electrophysiological nerve identification was performed in 32 patients using electric stimulation under processed electromyography of IAS (e-TaTME). RESULTS: The indication profile for TaTME was comparable between the v-TaTME and the e-TaTME group. The identification of IRP was more meaningful under electrophysiological assessment than under visual assessment for the left pelvic side (81% vs. 45%, p = 0.008) as well as the right pelvic side (78% vs. 45%, p = 0.016). The identification rates for PSN did not significantly differ between both groups, respectively (81% vs. 75%, p = 0.420 and 84% vs. 70%, p = 0.187). CONCLUSIONS: The transanal approach facilitated visual identification of IAS nerve supply. In combination with electrophysiological nerve assessment the identification rate almost doubled. For further insights functional data are needed.

Current status: new technologies for the treatment of patients with fecal incontinence.

Fecal incontinence is a frequent and debilitating condition that may result from a multitude of different causes. Treatment is often challenging and needs to be individualized. During the last several years, new technologies have been developed, and others are emerging from clinical trials to commercialization. Although their specific roles in the management of fecal incontinence have not yet been completely defined, surgeons have access to them and patients may request them. The purpose of this project is to put into perspective, for both the patient and the practitioner, the relative positions of new and emerging technologies in order to propose a treatment algorithm.

Low-anterior-resection syndrome. How does neoadjuvant radiotherapy and low resection of the rectum influence the function of anal sphincters in patients with rectal cancer? Preliminary results of a functional assessment study.

UNLABELLED: The aim of the study was to assess the influence of neoadjuvant radiotherapy and resection of the rectum on the functional parameters of anal sphincters. MATERIAL AND METHODS: 20 patients with rectal cancer, qualified for low anterior rectal resection with neoadjuvant radiotherapy were enrolled in the study group. The study protocol included an anorectal manometry, electromyography and fecal incontinence questionnaire (FISI) before radiotherapy, after radiotherapy, and after the operation. RESULTS: Of the 20 patients 12 were included in the final analysis, because 8 patients were re-qualified to abdomino-perineal resection of the rectum after neoadjuvant treatment. There were no significant changes in anal pressures assessed 5 to 8 days after radiotherapy. In 3 cases (25%) pathological changes in RAIR reflex were found in the manometric examination. After low anterior resection mean basal anal pressures were significantly lower, whereas squeeze anal pressures did not change significantly. In 7 patients (58%) the RAIR reflex was pathological or even absent after low anterior resection. Changes in manometric parameters correlated with FISI incontinence assessment after the operation. In electromyographic examination action potentials of motoric units of the external anal sphincter were still present both after radiotherapy, and after operation. CONCLUSIONS: Fecal incontinence after low anterior resection of the rectum seems to be caused mostly by changes in autonomic functionality of anal sphincters and lack of compliance of the neorectum, since the influence of neoadjuvant radiotherapy and the operation itself on the somatic innervation of anal sphincters seems to be minimal.

Total mesorectal excision with intraoperative assessment of internal anal sphincter innervation provides new insights into neurogenic incontinence.

BACKGROUND: The aim of this prospective study was to assess internal anal sphincter (IAS) innervation in patients undergoing total mesorectal excision (TME) by intraoperative neuromonitoring (IONM). STUDY DESIGN: Fourteen patients underwent TME. IONM was carried out through pelvic splanchnic nerve stimulation under continuous electromyography of the IAS. Anorectal function was assessed with the digital rectal examination scoring system and a standardized questionnaire. RESULTS: Nine of 11 patients who underwent low anterior resection had positive IONM results, with stimulation-induced increased IAS electromyographic amplitudes (median 0.23 µV (interquartile range [IQR] 0.05, 0.56) vs median 0.89 µV (IQR 0.64, 1.88), p < 0.001) after TME. The patients with the positive IONM results were continent after stoma closure. Of 2 patients with negative IONM results, 1 had fecal incontinence after closure of the defunctioning stoma and received a permanent sigmoidostomy. In the other patient the defunctioning stoma was deemed permanent due to decreased anal sphincter function. In 3 patients who underwent abdominoperineal excision, IONM assessed denervation of the IAS after performance of the abdominal part. CONCLUSIONS: This study demonstrated that IONM of IAS innervation in rectal cancer patients is feasible and may predict neurogenic fecal incontinence.

Sacral nerve stimulation for faecal incontinence: patient selection, service provision and operative technique.

AIM: Faecal incontinence is estimated to affect between 2 and 3% of Western adult populations. In recent years sacral nerve stimulation has become an important treatment modality, often as the first-line surgical therapy. The aim of this article was to review the current evidence regarding patient selection and surgical technique and to evaluate the logistics of providing a neurostimulation service. METHOD: A Medline search was performed including the keywords and/or MeSH headings of sacral nerve stimulation, neuromodulation, artificial pacemaker, faecal incontinence, patient selection, predictive factors and anal canal. Further studies were identified by cross-referencing from relevant articles and by appraisal of recent peer-reviewed conference abstracts and proceedings. RESULTS: Despite the success of sacral nerve stimulation for several pathophysiological causes of incontinence, case selection is of paramount importance. Sacral nerve stimulation should not be offered outside a multidisciplinary pelvic floor unit. Temporary evaluation using diary cards can lead to false positive and negative results. Adherence to a meticulous surgical technique, using low amplitude stimulation to guide lead placement, provides optimal clinical outcome. CONCLUSION: The short-term outcome of sacral nerve stimulation is dependent on patient factors and operative technique. Despite this, specific preoperative predictive factors of treatment success have yet to be identified.

A bi-directional assessment of the human brain-anorectal axis.

BACKGROUND: Brain-gut dysfunction has been implicated in gastrointestinal disorders but a comprehensive test of brain-gut axis is lacking. We developed and tested a novel method for assessing both afferent anorectal-brain function using cortical evoked potentials (CEP), and efferent brain-anorectal function using motor evoked potentials (MEP). METHODS: Cortical evoked potentials was assessed following electrical stimulations of anus and rectum with bipolar electrodes in 26 healthy subjects. Anorectal MEPs were recorded following transcranial magnetic stimulation (TMS) over paramedian motor cortices bilaterally. Anal and rectal latencies/amplitudes for CEP and MEP responses and thresholds for first sensation and pain (mA) were analyzed and compared. Reproducibility and interobserver agreement of responses were examined. KEY RESULTS: Reproducible polyphasic rectal and anal CEPs were recorded in all subjects, without gender differences, and with negative correlation between BMI and CEP amplitude (r -0.66, P=0.001). Transcranial magnetic stimulation evoked triphasic rectal and anal MEPs, without gender differences. Reproducibility for CEP and MEP was excellent (CV <10%). The inter-rater CV for anal and rectal MEPs was excellent (ICC 97-99), although there was inter-subject variation. CONCLUSIONS & INFERENCES: Combined CEP and MEP studies offer a simple, inexpensive and valid method of examining bidirectional brain-anorectal axes. This comprehensive method could provide mechanistic insights into lower gut disorders.

Sacral neuromodulation for the treatment of fecal incontinence: analysis of cost-effectiveness.

PURPOSE: The cost-effectiveness and budget impact of introducing sacral nerve modulation (SNM) as a treatment for fecal incontinence in Italy were evaluated in a simulation model. METHODS: A decision-analysis model with a Markov submodel was used to represent clinical pathways for treatment of patients with fecal incontinence in a scenario with SNM and a scenario without SNM. Data were obtained from published studies and from an expert panel. Evaluation of resource consumption was conducted from the perspective of the Italian National Health Service, and costs were retrieved from the Italian NHS procedures reimbursement list. The time horizon was 5 years, and a 3% discount rate was applied to costs and outcomes. Effectiveness was measured in symptom-free years and in quality-adjusted life-years (QALYs). Fecal incontinence prevalence data and SNM usage forecasts were used to estimate budget impact over the next 5 years. RESULTS: The incremental cost-effectiveness ratio for introducing SNM was €28,285 per QALY gained for patients with a structurally deficient anal sphincter and €38,662 per QALY gained for patients with intact anal sphincters. If a threshold of €40,000 per QALY gained is set as the level that a decision-maker would regard as cost-effective, the probability that the introduction of SNM will be cost-effective would be 99% for patients with a structurally deficient sphincter and 53% for patients with an intact sphincter. Budget impact analysis showed that introducing SNM would have an estimated budget impact of 0.56% over 5 years on the budget allocated for fecal incontinence treatment. CONCLUSION: Our data show SNM to be an efficient investment with an acceptable incremental cost-effectiveness ratio and a limited impact on the total allocated budget for fecal incontinence.

Sexual dimorphism and hormone responsiveness in the spinal cord of the socially monogamous prairie vole (Microtus ochrogaster).

Prairie voles (Microtus ochrogaster) are exceptional among rodents in that many aspects of their brain and behavior are not masculinized by exogenous aromatizable androgens. However, the sexually differentiated endpoints studied to date rely on estrogenic mechanisms in other mammals. We examined whether sexual differentiation of an androgen receptor-dependent sex difference would be similarly distinct in prairie voles. Male mammals have more and larger motoneurons projecting to perineal muscles than do females. This sex difference normally arises from males' perinatal androgen exposure and can be eliminated by treating developing females with androgens. Gross dissection revealed bulbospongiosus muscles in adult male, but not female, prairie voles. Retrograde tracing from males' bulbocavernosus muscles and the external anal sphincter from both sexes revealed sexually dimorphic populations of labeled motoneurons in the ventral horn of the lumbar spinal cord. Similar to other rodents, males had twice as many motoneurons as females, although no sex difference in motoneuron size was detected. Unexpectedly, prenatal or early postnatal exposure to testosterone propionate had no effect on adult females' motoneuron number or size. In adulthood, gonadectomy alone or followed by chronic testosterone treatment also had no effect on females' motoneuron size or number, although castration reduced motoneuron size in males. Comparing gonadally intact weanlings confirmed that the sex difference in motoneuron number exists before adulthood. As with some other sexually dimorphic traits, and perhaps related to their unique social organization, sexual differentiation of the prairie vole spinal cord differs from that found in most other laboratory rodents.

Cost-effectiveness analysis of sacral neuromodulation (SNM) with Interstim for fecal incontinence patients in Spain.

INTRODUCTION: Fecal incontinence (FI) is a condition with a high impact on the psychological and social life of healthy people. Interstim, the sacral neuromodulation (SNM) therapy, has shown higher effectiveness and safety rates than surgical procedures like dynamic graciloplasty or artificial anal sphincter in patients with intact anal sphincter (IAS) and after sphincteroplasty in patients with structurally deficient anal sphincter (SDAS). OBJECTIVE: To assess the cost-effectiveness of FI management in two scenarios - with and without SNM - and to estimate the potential budget impact of its progressive introduction in the Spanish setting. METHODS: Two decision analytical models were developed (IAS and SDAS patients) representing the possible clinical paths for each of the scenarios (with and without SNM), as well as its clinical and economic consequences in the mid-to long term with a Markov model. Clinical and resource use data were retrieved from the literature and validated by a clinician expert panel. Effectiveness was measured with both QALYs and symptom-free years (SFY). A 3% discount rate was used for future costs and benefits (time horizon = 5 years). Prevalence figures were combined with Interstim sales forecasts to estimate the total number of patients to receive therapy over the next 5 years and the associated budget impact. RESULTS: The introduction of Interstim in the therapeutic management of FI has an associated cost-effectiveness of euro16 181 (IAS patients) and euro22 195 (SDAS patients) per QALY gained. The progressive introduction of Interstim in 75 to 100 patients/year will have an estimated budget impact of 0.1% of incremental costs in patients with FI. CONCLUSIONS: Introducing Interstim in the management of FI in IAS and SDAS patients in the Spanish setting has shown to be an efficient measure with an incremental cost-effectiveness ratio below the accepted Spanish threshold (around euro35 000/QALY), and with a relatively low additional cost for the Spanish NHS.

Assessment of the rectoanal inhibitory reflex in preterm infants with delayed meconium passage.

BACKGROUND: There is an inverse relationship between gestational age, birth weight and the time of first neonatal bowel movement. The authors hypothesized that delayed passage of meconium might result from a delayed maturation of the recto-anal inhibitory reflex (RAIR) in premature infants. OBJECTIVE: To evaluate whether the RAIR is absent in very preterm infants 28-32 weeks postmenstrual age with delayed meconium production. STUDY DESIGN: Anorectal manometry was performed in 10 preterm infants (seven male) with delayed meconium production (no meconium in the first 48 hours). Median postmenstrual age was 30 weeks (28-31 weeks). Birth weight ranged from 780 to 1930 g (median, 1395 g). A micromanometric assembly (outer diameter, 2.0 mm) was used which incorporated a 1.5-cm-long sleeve sensor for measurement of resting anal sphincter pressure and relaxation. Four side-holes recorded anal and rectal pressures. Rectal distension was performed with direct air insufflation to elicit the RAIR. RESULTS: The time from birth to passage of meconium ranged from 48 to 105 hours (median, 82 hours). The mean anal sphincter pressure, rectal pressure, and anal sphincter oscillation frequency were 22.0 +/- 5.0 mm Hg, 6.9 +/- 2.0 mm Hg, and 9.8 +/- 1.9/min, respectively. A normal RAIR was elicited in all infants. CONCLUSION: Anorectal manometry recordings in premature infants with delayed passage of meconium showed normal anorectal pressures and a normal RAIR, suggesting that delayed meconium passage is not related to the absence of a RAIR.

Anesthesia for ambulatory anorectal surgery.

The prevalence of minor anorectal diseases is 4-5% of adult Western population. Operations are performed on ambulatory or 24-hour stay basis. Requirements for ambulatory anesthesia are: rapid onset and recovery, ability to provide quick adjustments during maintenance, lack of intraoperative and postoperative side effects, and cost-effectiveness. Anorectal surgery requires deep levels of anesthesia. The aim is achieved with 1) regional blocks alone or in combination with monitored anesthesia care or 2) deep general anesthesia, usually with muscle relaxants and tracheal intubation. Modern general anesthetics provide smooth, quickly adjustable anesthesia and are a good choice for ambulatory surgery. Popular regional methods are: spinal anesthesia, caudal blockade, posterior perineal blockade and local anesthesia. The trend in regional anesthesia is lowering the dose of local anesthetic, providing selective segmental block. Adjuvants potentiating analgesia are recommended. Postoperative period may be complicated by: 1) severe pain, 2) urinary retention due to common nerve supply, and 3) surgical bleeding. Complications may lead to hospital admission. In conclusion, novel general anesthetics are recommended for ambulatory anorectal surgery. Further studies to determine an optimal dose and method are needed in the group of regional anesthesia.

Assessment of sphincter muscle function before and after posterior sagittal anorectoplasty using a magnetic spinal stimulation technique.

PURPOSE: The authors used a magnetic spinal stimulation technique to assess both the preoperative sphincter function and the effect of operative intervention on the sphincter muscle in patients with anorectal malformations. METHODS: The authors examined 5 patients with an anorectal malformation consisting of 4 high-type cases and 1 intermediate-type case, that all had undergone posterior sagittal anorectoplasty during the previous 2-year period. Control data also were obtained from 11 age-matched healthy children. A contraction of the external anal sphincter (EAS) was evoked by magnetic stimulation of the sacral roots with a figure-of-eight coil at the level of the lumber and sacral segments. EAS electromyograms then were recorded at the anal verge. RESULTS: The preoperative motor latencies at L4 stimulation increased significantly more in the patients than in the controls (5.9 +/- 0.5 msec v 4.1 +/- 0.7 msec during left side recording). In the postoperative examination (1 to 5 months after operation), the mean maximum amplitude decreased slightly without any significant difference, where as the latency was almost identical to the preoperative data. CONCLUSION: These results suggest that the neurologic function of EAS was congenitally disturbed, and the current operative technique had no significant effect on the sphincter function.

Anal vector volume analysis complements endoanal ultrasonographic assessment of postpartum anal sphincter injury.

BACKGROUND: The aim of this study was to determine the role of anal vector manometry in the assessment of postpartum anal sphincter injury and to establish the most suitable method of anal vector volume analysis for identifying significant external anal sphincter (EAS) injury in an at-risk parous population. METHODS: A total of 101 consecutive women with a history of instrumental or traumatic vaginal delivery was recruited. Anal ultrasonography and anal vector manometry were performed. Receiver-operator characteristic curves were used to determine the usefulness of anal manometry and anal vector volume analysis in the identification of significant EAS disruption (full thickness, more than one quadrant involved) detected by ultrasonography. RESULTS: Seventeen women had significant EAS disruption identified by anal ultrasonography. Anal vector manometry provided complementary functional information. Anal vector symmetry index (VSI), determined by analysis of mean maximum squeeze pressure, yielded 100 per cent sensitivity for significant EAS disruption, with a positive predictive value of 61 per cent. CONCLUSION: Anal vector manometry complements endoanal ultrasonography. VSI, determined by means of the squeeze pressure profile, correlates best with significant EAS disruption identified at anal ultrasonography.

Use of vector volume manometry and endoanal magnetic resonance imaging in the adult female for assessment of anal sphincter dysfunction.

PURPOSE: This study compared conventional water-perfused and vector volume anal manometry in female patients with neurogenic fecal incontinence and chronic anal fissure and in healthy female volunteers. We used endoanal magnetic resonance (MR) imaging to measure internal and external sphincter lengths and thicknesses and contrasted these with the manometric findings in the different anorectal conditions. METHODS: One hundred thirty-three female subjects were studied over an eight-month period, including 33 control volunteers, 83 patients with neurogenic fecal incontinence, and 17 patients with chronic anal fissure. Conventional manometry was contrasted with automated vector volume-derived parameters. Endoanal magnetic resonance images were obtained using a previously described internal coil with a 0.5 T Asset scanner measuring quadrantal internal sphincter thickness and averaged coronal internal and external sphincter lengths. RESULTS: There was a statistically significant relationship between parameters measured by conventional manometry and those variables derived from vector volume manometry at rest and squeeze. There was no difference in sectorial vector-derived pressures within any anorectal condition and no correlation between quadrantal internal sphincter thickness measurements and sectorial pressures at rest. Patients with chronic anal fissure and neurogenic fecal incontinence had constitutionally shorter superficial and subcutaneous external sphincters than healthy control subjects (P < 0.001). CONCLUSIONS: There is no association between manometric findings and morphologic sphincter measurement; however, the shorter distal external sphincter in patients with fissure might render the lower anal canal relatively unsupported after internal sphincterotomy in the female patient.

Combining the strength-duration curve of the external anal sphincter with manometry for the assessment of faecal incontinence.

BACKGROUND: The strength-duration curve of a muscle is thought to be a measure of its innervation. This study was designed to evaluate the ability of the strength-duration curve of the external anal sphincter to discriminate between controls and patients with faecal incontinence. METHODS: Forty-three women with faecal incontinence due to sphincter weakness were studied together with 45 age-matched women with no disorders of defaecation. Strength-duration curves of the external anal sphincter and anorectal manometry were recorded for all subjects with the additional measurement of pudendal nerve terminal motor latency in the incontinent group. RESULTS: Logistic regression was performed using resting and voluntary squeeze pressures and current strengths at 28 different pulse durations to develop a predictive equation for incontinence. Only currents at 1 and 6 ms were significant predictors. When anorectal manometry data were included, only the current required to elicit contraction at 1 ms was necessary. The following regression equation can be applied to predict continence in this population with a sensitivity of 95 per cent and a specificity of 100 per cent: logit(P)=4.1605-(0.0559 x squeeze pressure)-(0.1755 x resting pressure)+0.8622I(1 ms). A negative value indicates continence. CONCLUSION: The strength-duration curve, when used in conjunction with anorectal manometry, may have a role in the investigation of faecal incontinence.

Assessment of the reliability of cerebral potentials evoked by electrical stimulation of the anal canal.

The aim of this study was to assess the reliability of cortical evoked potentials after electrical stimulation of the anal canal. Cortical evoked potentials were recorded on 243 patients presenting with perineal pain (28 patients), impotence (55 patients), anal incontinence (52 patients), urinary continence (30 patients), constipation (49 patients), and on 29 neurological patients, by stimulating the external anal sphincter and penis (or clitoris). The inter- and intra-observer reproducibility was studied by coding recordings interpreted by three different observers on two separate occasions. The influence of recording characteristics and clinical data were assessed. To study operator dependence, five operators investigated the patients. Only one of them was well trained in this technique. The interpretation of the coded curves by the observers was poorly reproducible in about 15% of cases, depending on time between the two readings and the quality of recordings. The interpretation of cerebral responses after anal stimulation were observer-dependent and influenced by the knowledge of clinical data. This was also observed with cortical evoked potentials after electrical stimulation of the penis or clitoris, but to a lesser extent. The cerebral evoked potentials method was also operator-dependent, mainly after anal stimulation. When a study of cortical evoked potentials by perineal stimulation is needed in clinical practice, it seems logical to prefer cortical evoked potentials by penile or clitoral stimulation as they seem easier to obtain than those evoked by anal stimulation if the investigators are not well trained for the performance of electrophysiological studies as the former are much less operator- and observer-dependent.

[Value of anorectal manometry in assessment of constipation in childhood]. / Stellenwert der anorektalen Manometrie bei der Abklärung der Obstipation im Kindesalter.

We studied retrospectively 210 anorectal manometries of constipated children. Of the 87 patients with an anal fissure or a functional constipation, 83 had normal sphincter relaxation. All of the 23 patients with Hirschsprung's disease lacked the sphincter relaxation, as well as 22 of the patients with a dysganglionosis. Eleven patients with innervation defects showed pathologic sphincter contractions. Anorectal manometry is a valuable tool to differentiate between innervation defects and constipation of other etiologies.