Paediatric constipation for adult surgeons - article 2: new microscopic abnormalities and therapies

Constipation in childhood

Constipation in children is an often long-lasting pediatric functional gastrointestinal disorder with a worldwide prevalence varying between 0.7% and 29.6%, and estimated health-care costs of US$3.9 billion per year in the USA alone. The pathophysiology of childhood constipation is multifactorial and remains incompletely understood; however, withholding of stools, starting after an experience of a hard, painful, or frightening bowel movement is the most common cause found in children. A thorough medical history and physical examination, including a rectal examination in combination with a bowel diary, is sufficient in the majority of cases to diagnose constipation. The current standard treatment consists of education, toilet training, disimpaction, maintenance therapy and long-term follow-up. In the past decade, well-designed treatment trials in the pediatric population have emerged and long-term outcome studies have been completed. This Review summarizes the current knowledge of the clinical aspects of childhood constipation, including pathogenesis, diagnosis and treatment, with particular emphasis on the latest available data.

Paediatric and adult colonic manometry: A tool to help unravel the pathophysiology of constipation

Colonic motility subserves large bowel functions, including absorption, storage, propulsion and defaecation. Colonic motor dysfunction remains the leading hypothesis to explain symptom generation in chronic constipation, a heterogeneous condition which is extremely prevalent in the general population, and has huge socioeconomic impact and individual suffering. Physiological testing plays a crucial role in patient management, as it is now accepted that symptom-based assessment, although important, is unsatisfactory as the sole means of directing therapy. Colonic manometry provides a direct method for studying motor activities of the large bowel, and this review provides a contemporary understanding of how this technique has enhanced our knowledge of normal colonic motor physiology, as well as helping to elucidate pathophysiological mechanisms underlying constipation. Methodological approaches, including available catheter types, placement technique and recording protocols, are covered, along with a detailed description of recorded colonic motor activities. This review also critically examines the role of colonic manometry in current clinical practice, and how manometric assessment may aid diagnosis, classification and guide therapeutic intervention in the constipated individual. Most importantly, this review considers both adult and paediatric patients. Limitations of the procedure and a look to the future are also addressed.

Standard medical therapies do not alter colonic transit time in children with treatment-resistant slow-transit constipation

BACKGROUND

Slow transit constipation (STC) is a form of chronic constipation characterised by prolonged passage of faecal matter through the colon. It is diagnosed by demonstrating delayed colonic transit on gastrointestinal transit studies. Traditionally, radio-opaque marker studies are performed. Recently, radioisotope nuclear transit studies (NTS) have been used in our centre to assess gastrointestinal transit time. This study aimed to evaluate if there are changes in colonic transit in STC children resistant to standard medical treatment over a prolonged period.

METHODS

Children with STC resistant to standard medical therapy for > or =2 years who had undergone two separate NTS to assess their colonic transit (where the first study had identified slow colonic transit without anorectal retention) were identified after ethical approval. The geometric centre (GC) of radioisotope activity at 6, 24, 30 and 48 h was compared in the two transit studies to determine if changes occurred.

RESULTS

Seven children (4 males) with proven STC resistant to standard medical therapy and two transit studies performed at different times were identified. Mean age was 7.0 years (5.4-10.8 years) at first study, and 11.4 years (9.7-14.2 years) at second study, with a mean of 4.4 years (1-8.5 years) between studies. There was no significant difference in colonic transit at any timepoint in the two tests (paired t test).

CONCLUSIONS

We conclude that nuclear transit studies are reproducible in assessing slow colonic transit in children with treatment-resistant STC and demonstrate that conventional medical treatment over many years has no effect on underlying colonic motility.

Interstitial Cells of Cajal and their Role in Veterinary Gastrointestinal Pathologies

This study highlights the importance of interstitial cells of Cajal (ICs) in gastrointestinal disease. Human research is already considering IC pathologies but in veterinary research IC pathologies are rarely studied. Nevertheless, recent studies of ICs show a growing interest in the pathophysiology of gastrointestinal diseases and emphasize the consideration of this cell type in the pathophysiology of veterinary gastrointestinal malfunctions.

The antegrade continence enema successfully treats idiopathic slow-transit constipation

BACKGROUND

Antegrade continence enemas (ACEs) are successful for constipation and/or fecal incontinence caused by anorectal malformations or spina bifida but have been thought to be less successful in the treatment for patients with colonic dysmotility. We studied the long-term efficacy of ACE in a large group of patients with idiopathic slow-transit constipation (STC).

METHODS

We identified 56 children with an appendicostomy for ACE with radiologically proven STC. An independent investigator (SKK) performed confidential telephone interviews.

RESULTS

We assessed 42 of 56 children (31 boys) of mean age 13.1 years (range, 6.9-25). Mean follow-up was at 48 months (range, 3-118). Mean symptom duration before appendicostomy was 7.5 years (range, 1.4-17.4). Indications for appendicostomy were soiling (29/42), inadequate stool evacuation (7/42), and recurrent hospital admissions for nasogastric washouts (6/42). Both quality of life (Templeton quality of life [P < .0001]) and continence (modified Holschneider continence score [P < .0001]) improved with ACE. Soiling frequency decreased in 32 of 42 (11/32 completely continent). Thirty-seven of 42 children had reduced abdominal pain severity (P < .0001) and frequency (P < .0001). Complications included granulation tissue (33/42), stomal infection (18/42), and washout leakage (16/42). Fifteen of 42 children ceased using the appendicostomy (7/15 symptoms resolved). Thirty-five of 42 families felt that their aspirations had been met.

CONCLUSIONS

Antegrade continence enemas were successful in 34 (81%) of 42 children with STC, contradicting views that ACEs are less effective in patients with colonic dysmotility.