When invited to coordinate this issue of Pediatric Armais, my immediate reaction was that there was no great need for another compendium devoted to the subject of diarrhea in children since the subject has been repeatedly and extensively reviewed. However, a service may still be rendered to the practicing pediatric community through focus on specific troublesome or controversial aspects of the subject. I therefore chose the topics about which I am most frequently questioned during question and answer sessions at formal presentations. We have been able to secure authors who have demonstrated leadership in elucidating these specific subjects.
The shift toward realization that viruses are the major etiology of much of infantile diarrhea, when coupled with the lack of ability of most clinical facilities specifically to identify these agents, has left the subject in a somewhat confused state. Dr. Richard Hamilton, the distinguished pediatric gastroenterologist from the University of Toronto, has been a major contributor in describing the role of viruses in infantile diarrhea. We have asked him to outline the incidences, clinical courses, and pathogenetic roles associated with these agents.
A second contentious pathogenetic mechanism for infant diarrhea relates to the role of allergic phenomena. Some believe that considerable common gastrointestinal (GI) symptomatology, including diarrhea, is attributable to allergy while others take a dim view of calling any such symptom allergic. Dr. Joyce Gryboski, of Yale University, author of a standard classic textbook of Pediatric Gastroenterology, has been associated with descriptions of bloody diarrhea of neonates attributable to cow milk, with examinations for coproantibodies, and with other studies of allergic manifestations in the GI tract. She has agreed to put this subject into an appropriate perspective for the practitioner.
Presence of blood in the stool adds an element in acute or chronic diarrhea which is usually so disturbing that it induces a different and often not well-thoughtout approach to the differential diagnosis and management. We asked Dr. Arnold Silverman, Chief of Pediatrics at Denver General Hospital and co-author of an important text in Pediatric Gastroenterology to focus on this one question, ie, how should the presence of blood influence our approach to diarrhea? He has responded with a careful examination of the subject, focusing primarily on the bacteria responsible for bloody diarrhea.
The subject of water and mineral metabolism in diarrhea and its treatment is not in as great dispute in 1985 as it was formerly. However, the question of when to treat parenterally or when to hydrate orally, which hydration regimen to use and how soon may it be started, and the question of caloric nutrition in the face of diarrhea are unresolved problems. Specifically, the subject of which routes of administration and regimens may be useful at home has been extensively studied by Dr. Marvin Ament, Chief of Gastroenterology at the Los Angeles Children's Hospital. He offers his approach to the topic.
Finally, it is a source of continued confusion how lactose ingestion may play a role in diarrhea. At what age do patients with hereditary "adult type" lactase insufficiency manifest symptoms? Are these symptoms sometimes associated with constipation and abdominal pain as well as with diarrhea and if so, how does one know whether to expect diarrhea or constipation in a particular patient? Are there differences in the management of carbohydrate related infant diarrhea and that of older lactase-deficient individuals? Attempts to answer these and similar questions on this subject come from our own laboratory and clinic. My associate, Dr. Anastasios Angelides and I have hopefully succeeded in organizing the confusing elements into an understandable and clinically useful framework.