Epidemiology of inflammatory bowel diseases in childhood.

Inflammatory Bowel Disease (IBD) is common in most industrialised countries and childhood IBD accounts for nearly 30% of total cases. Various studies, mostly from Europe and USA have reported epidemiological characteristics of childhood IBD. The incidence figures vary greatly from region to region and within a region over time. Almost all reported studies have documented an increase in the incidence, mainly of Crohn's disease over the last few decades. The reasons for the increase are not clear but epidemiological observations have led to many postulates. Incidence in developing countries is perceived to be low, but limited data suggest that it may not be as uncommon as previously thought. IBD can occur at any age but is rare in infancy. Among childhood IBD, early onset IBD appears to be different epidemiologically and is characterised by predominance of colonic involvement and high positive family history. It has become apparent that only about 25% of childhood Crohn's disease presents with classical triad of abdominal pain, diarrhoea and weight loss. Pediatricians should be aware of atypical manifestations and should maintain high index of suspicion. Though epidemiological studies of childhood IBD done so far have contributed towards understanding of IBD, they have differed in study design, population, time period, age group and case definitions. Unfortunately there are no uniform, clear diagnostic criteria which are evidence based. To address this problem, recently the IBD working group of European Society of Pediatric Gastroenterology, Hepatology and Nutrition (ESPGHAN) has published "The Porto Criteria" which details a consensus based diagnostic criteria for the diagnosis of childhood IBD. This should bring uniformity in ascertainment of newly diagnosed IBD cases. An European multicentre prospective database has also been established to facilitate future epidemiological studies.

Newer diarrheal syndromes.

Aetiological diagnosis of protracted diarrhoea remains obscure in as many as 30% of cases despite extensive investigations. A number of newer syndromes have been recognized amongst this "idiopathic group" which includes microvillous inclusion disease, "tufting" enteropathy and epithelial dysplasia, autoimmune enteropathy and "syndromic" immunodeficiency with characteristic facial abnormalities, woolly hair and intractable diarrhea. The molecular basis of some of these syndromes has been reviewed but in only a small series of patients has the functional defect been characterized. If a case is suspected the antenatal history, family history and history of consanguinity should be sought. Extra-intestinal manifestations, presence of gut or other auto-antibodies, together with phenotypic abnormalities should be looked for. Careful light and electron microscopy is done of small bowel biopsies, although microvillous inclusion disease can be usually suspected on PAS staining. Large bowel biopsy may be needed to exclude an unsuspected microscopic colitis. The prognosis of this group of conditions is poor with an overall 50-85% mortality. Although successful gut transplantation has been reported, genetic counselling may be one of the more important aspects of the clinicians' role.

Gastroesophageal reflux in children.

Gastroesophageal reflux (GOR) is a major cause of morbidity and failure to thrive particularly in neurologically impaired children. Clinical manifestations of GOR in children range from regurgitation, food refusal, irritability, failure to thrive, hematemesis, wheezing and aspiration pneumonia, apnoea and apparent life threatening events in infants to clinically silent reflux. Although, no one test is always best to diagnose GOR, 24 hour esophageal pH monitoring remains the 'gold standard' for diagnosis. Barium radiography is useful for the diagnosis of associated anatomical abnormalities and endoscopy enables a histological diagnosis of esophagitis. Therapy for gastroesophageal reflux disease is now well established. Proper positioning of the baby and thickening of feeds is beneficial in uncomplicated GOR. Prokinetic agents like cisapride should be tried if dietary management and antacids are ineffective. Metoclopramide or domperidone may be tried in neurologically impaired children. H2-receptor antagonists are indicated in GOR complicated by esophagitis. Ranitidine is regarded to be more potent. Cimetidine has additional spectrum of adverse effects and sufficient information is not available on famotidine. Omeprazole has been shown to be effective in treating GOR-esophagitis resistant to H2 antagonist therapy even in high risk patients.