Mucosal nerve deficiency in chronic childhood constipation: a postmigration defect?

The pathogenesis of Hirschsprung's disease-associated enterocolitis

Hirschsprung's disease-associated enterocolitis (HAEC) remains the most life-threatening complication in Hirschsprung disease (HD) patients. The pathogenesis of HAEC has not been determined and many hypotheses regarding the etiology of HAEC have been proposed. These include a possible causal relationship between the abnormal enteric nervous system development in HD and the development of enterocolitis. Based on the complex genetic causes of HD that have been discovered and the resultant heterogeneous group of patients that exists, the causes of HAEC are likely multiple. New insights regarding the relationship of the role of the enteric nervous system and its interaction between intestinal barrier function, innate host immunity, and commensal microflora have been discovered, which may shed light on this perplexing problem. This review presents current known risk factors of HAEC and the proposed theories and supporting evidence for the potential etiologies of HAEC.

Quantitation of cellular components of the enteric nervous system in the normal human gastrointestinal tract--report on behalf of the Gastro 2009 International Working Group

BACKGROUND

Patients with gastrointestinal neuromuscular diseases may undergo operative procedures that yield tissue appropriate to diagnosis of underlying neuromuscular pathology. Critical to accurate diagnosis is the determination of limits of normality based on the study of control human tissues. Although robust diagnostic criteria exist for many qualitative alterations in the neuromuscular apparatus, these do not include quantitative values due to lack of adequate control data.

PURPOSE

The aim of this report was to summarize all relevant available published quantitative data for elements of the human enteric nervous system (neuronal cell bodies, glial cells, and nerve fibers) from the perspective of the practicing pathologist. Forty studies meeting inclusion criteria were systematically reviewed with data tabulated in detail and discussed in the context of methodological variations and limitations. The results reveal a lack of concordance between observations of different investigators resulting in data insufficient to produce robust normal ranges. This diversity highlights the need to standardize the way pathologists collect, process, and quantitate neuronal and glial elements in enteric neuropathologic samples, as suggested by recent international guidelines on gastrointestinal neuromuscular pathology.

Recent advances in chronic constipation

PURPOSE OF REVIEW

Chronic constipation remains one of the most frequent complaints in primary and subspecialty pediatric clinics. It is associated with significant emotional and economic burden for both the children and the caregivers. Recently, advances have expanded our understanding of the pathophysiology and treatment options for children with chronic constipation. Here, we review current strategies addressing the cause, diagnostic technologies and treatments of chronic constipation.

RECENT FINDINGS

There is some new information presented here on techniques for diagnosis and long-term complications associated with chronic childhood constipation. Comparative data on current laxatives and the development of medications with novel mechanisms of action are reviewed for a glimpse into the horizon of possible new treatments for children with chronic constipation. Studies on effects of growth, quality of life, dietary fiber and symptoms, which may coexist with constipation, are discussed.

SUMMARY

The recent literature on chronic constipation has provided some new knowledge providing a more evidence-based approach to treating these patients. We review the scope of this problem and the estimated cost of treating constipation. The availability of long-term outcome data enhances our understanding of the natural history of this problem. Newer pharmacological approaches provide optimism for treatment for this common problem.