Helicobacter pylori is among the most common bacterial infections in humans. Helicobacter pylori is a Gram-negative, S -shaped rod .The most likely mode of transmission is fecal-oral or oral-oral. Helicobacter pylori infection is acquired in early life and continues to have a high prevalence, especially in developing countries. Growing antibiotic-resistant strains necessitate adapted treatments. The majority of children with Helicobacter pylori infection remain asymptomatic, although a percentage of the infected children do develop Helicobacter. pylori-associated diseases. Helicobacter pylori is closely associated with the development of gastritis, gastric or duodenal ulcers. Helicobacter pylori infection can manifest with abdominal pain or vomiting and, less often, refractory iron deficiency anemia or growth retardation. Helicobacter pylori can be associated, though rarely, with chronic autoimmune thrombocytopenia. Anemia, idiopathic thrombocytopenic purpura, short stature, and sudden infant death syndrome (SIDS) have also been reported as possible extra-gastric manifestations of Helicobacter pylori infection . The diagnosis of Helicobacter pylori infection is made histologically by demonstrating the organism in the biopsy specimens. 13 C-urea breath tests and stool antigen tests are reliable noninvasive methods of detecting Helicobacter pylori infection in patients who do not require endoscopic evaluation. However, some guidelines recommend that non-invasive assessment methods are reserved to determine whether Helicobacter pylori has been eradicated not for diagnosis .However Helicobacter pylori-associated gastritis may, however, be an incidental histopathologic finding during upper endoscopy performed for unrelated indications such as the diagnosis of inflammatory bowel disease, or celiac disease.

Inclusion Criteria:

- 1. Children and adolescents between 4 and 18 years old having chronic or reccurent unexplained dyspeptic symptoms (epigastric pain, post prandial fullness, early satiety, bleching, heart burn, bloating, flatulence, regurgitation, nausea, vomiting and/ or halitosis)(Miwa et al.,2012) and/ or non variceal hematemesis

2. The dyspeptic symptoms should be present at least 2months duration , which doesn't need to be consecutive, during the previous 6 months.(Rasquin et al., 2006)

Exclusion Criteria:

- 1. Patients who received anti sectertory drugs and/ or antibiotics in the previous 4 weeks before endoscopy.

2. Patients less than 4years and more than 18 years old.

The study will include children and adolescents recruited from the Gastroenterology, Hepatology And Endoscopy Unit at Assuit University, Children's Hospital.