RESUMEN
H.pylori was first identified and .recognized by marshal and warren in 1983 [1],recently, H.pylori antigen detection test in stool [HPS A] was reported to be a sensitive and reliable screening test for H.pylori infection as compared to urea breath test. This study was carried out on 3 groups of children aged 6 months-14 years selected from pediatric patients of Damnhour hospital. In group I [hematemesis] upper upper gastrointestinal endoscopy revealed mucosal erythema in 60% associated with antral nodularity in 4 patients. All patients who had a positive urease test [40%], had a histopathological diagnosis of chronic active full thickness gastritris. The results of endoscopic, histopathologic examination and rapid urease test in group II [RAP] showed mucosal erythema in 90% [18 patients], antral nodularity in 60% urease test was positive in 12 children [60%]. The results of HPS A showed that 30% of patients in group II had positive test. When these results were compared to the histopathologic and urease test and results of HpSA was 70%, specificity 100% +ve and -ve predictive values of 100, 75.2% respectively