Anorectal manometry with and without ketamine for evaluation of defecation disorders in children.

INTRODUCTION: Anorectal manometry (ARCM) provides valuable information in children with chronic constipation and fecal incontinence but may not be tolerated in the awake child. This study aimed to evaluate the effect of ketamine anesthesia on the assessment of anorectal function by manometry and to evaluate defecation dynamics and anal sphincter resting pressure in the context of pathophysiology of chronic functional (idiopathic) constipation and soiling in children. METHODS: This was a prospective study of children who were investigated for symptoms of chronic constipation and soiling between April 2001 and April 2004. We studied 52 consecutive children who had awake ARCM, biofeedback training and endosonography (awake group) and 64 children who had ketamine anesthesia for ARCM and endosonography (ketamine group). We age matched 31 children who had awake anorectal studies with 27 who had ketamine anesthesia. RESULTS: The children in awake and ketamine groups were comparable for age, duration of bowel symptoms and duration of laxative treatments. ARCM profile was comparable between the awake and the ketamine groups with regard to anal sphincter resting pressure, rectal capacity, amplitude of rectal contractions, frequency of rectal and IAS contractions and functional length of anal canal. Of 52 children who had awake ARCM, dyssynergia of the EAS muscles was observed in 22 (42%) and median squeeze pressure was 87mm Hg (range 25-134). The anal sphincter resting pressure was non-obstructive and comparable to healthy normal children. Rectoanal inhibitory reflex was seen in all children excluding diagnosis of Hirschsprung disease. CONCLUSIONS: Ketamine anesthesia does not affect quantitative or qualitative measurements of autonomic anorectal function and can be used reliably in children who will not tolerate the manometry while awake. Paradoxical contraction of the EAS can only be evaluated in the awake children and should be investigated further as the underlying cause of obstructive defecation in patients with chronic functional constipation and soiling.

Evaluation of outcome of anorectal anomaly in childhood: the role of anorectal manometry and endosonography.

The aim of this study was to evaluate role of anorectal manometry (ARM) and anal endosonography (ES) in assessment of the internal anal sphincter (IAS) quality on continence outcome following repair of anorectal anomalies (ARA). We devised a scoring system to evaluate the quality of the IAS based on ARM and ES and correlated the scores with clinical outcome, using a modified Wingfield score (MWS) for faecal continence. We also assessed the implication of megarectum and neuropathy on faecal continence. Of 54 children studied, 34 had high ARA and 20 had low ARA. Children with high ARA had poor sphincters on ES and ARM, and also poor faecal continence compared to those with low ARA. The presence of megarectum and neuropathy was associated with uniformly poor outcome irrespective of the IAS quality. The correlations between MWS on one hand, and ES and ARM scores for IAS on the other hand were weak in the whole study group, ES r = 0.27, P < 0.04, and ARM r = 0.39, P < 0.004. However, the correlations were strong in those who had isolated ARA without megarectum or neuropathy, ES r = 0.51, P < 0.02 and ARM r = 0.55, P < 0.01, respectively. In conclusion, the ARM and ES are valuable in evaluation of continence outcome in children after surgery for ARA and those with good quality IAS had better faecal continence. The IAS is a vital component in functional outcome in absence of neuropathy and megarectum.

Management of childhood constipation.

The effective management of constipation in childhood requires an understanding of the ways that the physical and psychological factors interact. The early difficulty with defecation that leads to pain, fear, and refusal to use the pot or lavatory often progresses to the formation of vicious cycles of increasing faecal retention as the rectum increases in capacity and the experience of passing large, hard stools is repeated. There is increasing distress as overflow faecal incontinence compounds the problem for the older child. The medical, psychological, and surgical management strategies are reviewed together with the rationale for their use.

Investigations for incontinence and constipation after surgery for Hirschsprung's disease in children.

Surgery for Hirschsprung's disease is associated with high rate of morbidity, in the form of either constipation or incontinence or a combination of the two. This study investigates the mechanisms responsible for incontinence and/or constipation following the pull-through operation for Hirschsprung's disease. There were 19 children (15 boys and 4 girls), who at the time of study; 16 had undergone Duhamel, 1 Rehbein, and 2 Soave operation. We classified patients according to their symptoms into 3 groups: Group A was incontinent of faeces; Group B was constipated and incontinent of faeces, and Group C was constipated only. The median age at referral was 6 years, and the median period after operation was 5 years. All patients were investigated by intestinal transit study, endoanal sonography and anorectal manometry. Group A had normal or rapid transit study, as opposed to Groups B and C, who had delayed-transit study. On endoanal sonography, all children had an intact internal and an external anal sphincter, below the level of pull-through operation. The anorectal manometry showed a significantly lower resting anal pressure in the incontinent Group A as compared to the constipated children with or without incontinence in Group B or C (38 mmHg versus 57 or 66 mmHg respectively). The rectal pressure was also significantly higher in children in Group A as compared to those in Group B or C (71 mmHg versus 42 or 36 mmHg). The ratio of rectal/anal pressure was higher in incontinent children in Group A, as compared to constipated children in Group B or C. Therefore, constipation can be caused by high anal resting pressure and a weak rectal peristalsis, while faecal incontinence can be secondary to poor compliance and elevated rectal pressure in the presence of normal or low anal sphincter resting pressure. Aperients are the mainstay of treatment of constipation, however, children with incontinence are more difficult to treat. We did not attempt to define the pattern of nerve plexus because of poor results of revision operation for residual hypoganglionic segment and intestinal neuronal dysplasia. Treatment of these children can become more rational, if furnished with detailed functional studies. We advocate investigation of the anorectal function at an early stage in symptomatic children after surgery for Hirschsprung's disease, and less invasive treatment should be considered before embarking on major surgery.

Evaluation of dysfunction following reconstruction of an anorectal anomaly.

To evaluate the utility of anorectal manometry (ARM) and magnetic resonance imaging (MRI) with an endocoil in the assessment of dysfunction in children with repaired anorectal anomalies (ARA), 15 patients aged 1 to 15 years with repaired ARAs and chronic faecal incontinence or constipation were prospectively recruited. They underwent clinical assessment using a modified Wingfield score (MWS). ARM and MRI with an endocoil and conventional external coil were carried out. The results of ARM alone, MRI alone, and a combination of ARM and MRI were correlated with the MWS. Manometric internal anal sphincter (IAS) scores determined from sphincter length and activity correlated with MWS (r = 0.56, P = 0.02); manometric scores of rectal peristaltic activity did not. Overall manometric score (IAS and rectal scores combined) showed a correlation with MWS (r = 0.55, P = 0.02). Endoanal MRI sphincter scores did not correlate with MWS, but the presence of a megarectum on MRI did (r = 0.44, P = 0.05). Overall MRI score did not correlate with MWS. Minor neurosacral anomalies were shown on MRI in 3 children who had poor functional scores. Combined manometric and MRI scores showed a correlation with MWS (r = 0.58, P = 0.01). ARM and MRI are potentially useful in the assessment of dysfunction of children with repaired ARAs. Both modalities require refinement and further assessment in the context of directing management.

Constipation in epidermolysis bullosa: successful treatment with a liquid fiber-containing formula.

In epidermolysis bullosa (EB), chronic constipation, painful defecation, and fecal impaction frequently contribute to malnutrition and growth failure. Standard treatments for constipation, such as increased intake of conventional dietary fiber and fluids and/or the use of laxatives and stool softeners, are largely unsuccessful. We evaluated by questionnaire the use of a fiber-containing liquid formula (Enrich) in 20 chronically constipated children with dystrophic EB. All derived substantial improvement in constipation when taking 250 to 750 ml Enrich per day. We recommend that such a fiber-containing food be prescribed for chronic constipation in EB. In cases of fecal impaction, this should be preceded by bowel cleansing.

Writing and marking examinations for paediatrics.

Examinations are an essential element of medical education, which generates vehement debate but unfortunately a relative lack of rigorous critical analysis. There appears to be a background anxiety that research findings that might suggest an examination has been less than fair will lead to endless arguments with candidates who have failed that examination. It is a major responsibility of all those involved in examining to seek evidence of the fairness, reliability, and validity of the methods and the organisation of the tests. Computers have made analysis of results much easier. Access to shared banks of all types of questions and answer sheets should allow examiners to select the subject first and the assessment tool second but from a range of tested and continually modified questions which allow comparison of candidates' performance both in time and between institutions. The creation of examination materials and their evaluation must be considered as valuable an activity as research in academic life. There is little point in child health research if the advances in knowledge and skills that this generates cannot be shown to have been acquired eventually by present and future paediatricians.

The clinical value of solid marker transit studies in childhood constipation and soiling.

Assessment of constipation in childhood is difficult, particularly when the presenting symptom is spurious diarrhoea or faecal incontinence. We have therefore assessed the clinical usefulness, reliability and acceptability of a solid marker transit technique in 52 patients with constipation (median age 8.0 years; range 2-13.5 years) at two referral centres. Median duration of symptoms was 60 months. Soiling was a prominent feature in 43 children (83%). Ten, 3 mm pieces of 6FG radio-opaque Silastic tubing were given orally at 9am on days 1, 2 and 3 and a plain abdominal film taken on day 5. Laxative treatment was not interrupted. Each film was divided into right colon, left colon and rectosigmoid areas, using bony landmarks, and the marker content of each area counted. The coefficient of variation of intra and inter-observer errors was 3.1% and 2.1% respectively. By day 5, 7% (group median) of markers were still in the right colon, 17% in the left colon and 42% in the rectosigmoid. Twenty-one patients (40%) had normal transit, 4 (8%) mild delay, 9 (17%) moderate and 18 (35%) severe transit delay. Marker distribution indicated slow pan-colonic transit in 29% and slow segmental transit in 10%. In 21%, clustering of markers in the rectosigmoid suggested outlet obstruction. A significant correlation was found between both transit delay and marker distribution and the severity of clinical symptoms of constipation and soiling. Repeat studies in six children following colonic evacuation revealed significant improvement (P < 0.05) in marker transit.(ABSTRACT TRUNCATED AT 250 WORDS)

Anorectal function of children with neurological problems. I: Spina bifida.

Anorectal function was assessed with anorectal manometry in 45 children with spina bifida (21 girls and 24 boys, mean age 11 1/2 years). 24 enuretic children served as controls. The pressure in the first and second centimeters of the anal canal was lower among index children than controls and also lower among those with high spinal lesions compared with those with low lesions. Rectal activity (rectal sensation and trace appearance) during rectal distension appeared to be reduced among index children; sensation was particularly poor among those with high spinal lesions. Manometry may be useful in children with spina bifida as it provides a clearer understanding of sphincter function and leads to a more rational approach to the management of bowel problems.

Anorectal function of children with neurological problems. II: cerebral palsy.

In response to the frequent complaint of difficulties with defecation experienced by children with cerebral palsy, 34 children (13 girls and 21 boys, mean age 10 years) with cerebral palsy were investigated by questionnaire and anorectal manometry. 24 enuretic children served as controls for the anorectal manometry. Constipation affected 26 of 29, defecation distress eight and faecal incontinence 16 of the index children, but incontinence was mild in most cases. Index children had a low resting pressure in the first centimetre of the anal canal, slow anal rhythmical activity and a pressure increase in the first centimetre during maximum rectal distension. These findings suggest anal sphincter and/or pelvic floor muscle incoordination, but no evidence of abnormal rectal function. The authors conclude that surgical intervention was not indicated for the index children, but that medical treatment could be improved.

Computer-assisted learning in medical education.

The advent of cheap and powerful micros has opened the possibility of computer-assisted learning (CAL) in medical education. This article attempts to demonstrate the educational value of CAL, with illustrations of its use. Four styles of CAL are examined, and the danger of trivializing the learning process discussed. The ultimate CAL package which enables students to take charge of their own learning is considered. There are considerable advantages in distance learning, self-assessment, computer-marked examinations and 'audit'. Some of the main problems are considered; these are decisions which must be taken about the choice of hardware and software. The use of various peripheral devices such as slide projectors and videodisc players greatly enhances the value of CAL material, as do alternative input devices. Some thought is given to software style in the presentation of material, and also to the question of the keeping of student records. The use of an author language facilitates program development, and the construction of content-free 'shell' programs enables new material to be added to existing frameworks. Other advantages of CAL include student access to JANET and the possibility of on-line searching of databases. CAL in medical education can help to liberate students from the burden of the rote learning of facts, and enhance the role of reason and imagination in the learning process.

Reflex anal dilatation associated with severe chronic constipation in children.

Data were collected from children with severe chronic constipation, and the appearance of the anus at presentation was noted. A visibly relaxed sphincter (indicating a degree of reflex anal dilatation) was seen in 20 children out of the 129 in whom this sign was sought. The only differentiating characteristic in this group of children was the greater degree of faecal loading judged on palpation of the abdomen. This evidence supports the hypothesis that constipation of such severity that it was referred to a specialised clinic can produce signs that may lead to an erroneous diagnosis of sexual abuse by anal penetration.