Introduction

This issue addresses colorectal problems commonly seen in infancy and childhood. In particular, the authors and I hope to address pediatric colorectal problems that carry a risk of long-term morbidity and thus may be seen by adult gastroenterologists and colorectal surgeons, as well as pediatric gastroenterologists and pediatric surgeons.

The congenital problems of Hirschsprung’s disease and anorectal anomalies present difficult long-term problems despite our increasingly sophisticated understanding of the etiology of Hirschsprung’s disease and an evolving appreciation of the altered anatomy and physiology in anorectal anomalies. Despite surgical ’success’ in treating the colorectal anomalies, this last decade has confirmed what many suspected. Too often, these children do not have normal bowel habits and face socially debilitating problems that can have serious psychological ramifications.

The historical evolution of surgery for the treatment of congenital anorectal problems demonstrates that physicians are continuously modifying approaches and techniques to achieve better outcomes for their patients. Bold and innovative approaches led from surgery for survival in the 19th and early 20th century to surgery for continence. While newer techniques are attempting to achieve normalcy, results continue to be suboptimal because of ongoing problems with incontinence, encopresis, as well as constipation and suggest that there is still much to be done to achieve an ideal outcome. The work of many groups, but particularly of Dr. Peña, has helped the pediatric community to understand that careful follow-up is necessary and additional surgical procedures may be needed to achieve the best possible outcome.

Drs. Masiakos and Ein have highlighted the signature historical events that occurred in the gradual understanding of Hirschsprung’s disease from the original clinical observation of infants who died from hypertrophy and dilatation of the colon, to the pioneering surgical approach of Dr. Swenson in the 1940s, as well as the works and thinking of other surgeons who have tried to refine Swenson’s original procedure, including laparoscopic and transanal approaches to the disease. Their article emphasizes our improved survival in Hirschsprung’s disease but acknowledges that there are long-term problems with evacuation in up to 25% of the children treated for aganglionosis.

In the last two decades with the advent of streamlined molecular genetics, extraordinary advances in the understanding of the development of the neurenteric system have occurred. Although animal models of aganglionosis had been reported in the 1960s, it was the serendipitous link of Hirschsprung’s disease in families with multiple endocrine neoplasias (MEN 2A) that cemented the ’genetic’ basis of this problem. This led to work identifying the importance of RET proto-oncogene and its product (tyrosine kinase receptor) in the development of the enteric neural network. Dr. Goldstein’s article expands on this seminal observation by looking at the molecular basis of many genes in the migration of nerve cells through the alimentary tract and highlights the delicate interaction of the nerve cells and the surrounding matrix.

This deeper understanding of the neural network may help to explain the continued problems with constipation and encopresis that plague a large percentage of children who have undergone operations for aganglionosis. If the neurenteric network is present but abnormal for varying distances above the zone of aganglionosis it behooves the pediatric surgery community to improve our ability to identify the appropriate level for the proximal surgical margin. With so many children having less than ideal outcomes following technically successful operations, it seems to demonstrate that the presence of ganglion cells is not enough. In the near future, this may mean the removal of ganglionated, but physiologically abnormal, large intestine.

The severity of the constipation that occurs after surgery for these congenital colorectal problems have led gastroenterologists and pediatric surgeons to more actively investigate the infant or child who does not do well after surgery. Parallel to this postoperative group is a subset of children without obvious anorectal abnormalities who have debilitating constipation. Both groups have similar clinical symptoms and are being more proactively investigated. While we continue to search for the elusive causes of refractory constipation in ’normal’ children, it is clear that the symptoms in a small percentage are sufficiently severe that surgical intervention is needed. However, the surgical therapy that will most likely lead to successful treatment can be uncertain. A systemic evaluation and approach to these children is the primary message of the article by Drs. Rodriguez and Flores. Behavior modification, pharmacological intervention, and occasionally extirpative surgery may be necessary in the treatment of the child with particularly refractory constipation. This same algorithm is appropriate to evaluate those children who have difficulties with evacuation complicating congenital colorectal problems.

The article of Drs. Zarroug and Moir with Ms. Stavlo examines the laparoscopic approach for the surgical treatment of children who have of severe ulcerative colitis or a polyposis syndrome. The problems following the ileal pouch anal anastomosis can be serious in the perioperative period but can persist as pouchitis, pouch retraction, or ileoanal stenosis. Pouchitis in particular has been a frustrating morbidity that complicates the surgical correction of the disease. Even still, the studies from the Mayo group has highlighted that the quality of life for these children by almost every indicator is significantly improved with the surgical treatment of their disease. In almost every category, except for parental anxiety, the children’s functional and psychological outcomes are statistically equivalent to control.

Finally, Dr. Russell addresses this problem of pouchitis that occurs in a significant number of children with ileal pouch anal anastomosis, particularly if the pouch is constructed for ulcerative colitis. Fortunately, therapy is often a limited course of oral antibiotics. However, in a few children pouchitis can be a chronic morbidity that is poorly controlled and may lead eventually to failure of the pouch. Dr. Russell’s overview of this problem offers insight into the modern treatment and his thoughts provide an outline to address this postoperative complication.

I would like to thank my colleagues in pediatric gastroenterology and pediatric surgery who have helped to address these pediatric colorectal diseases. Their reviews have helped to crystallize some of my own approaches to these difficult issues. I am hopeful that it will stimulate the readership to realize that despite our surgical success in the treatment of these problems, long-term morbidities persist and creative approaches to address these less than ideal outcomes are necessary.