Atrophic gastritis and chronic diarrhea due to Helicobacter pylori infection in early infancy: A case report.

Helicobacter pylori infection causes atrophic gastritis in childhood, but atrophic gastritis due to H pylori infection is extremely rare in infancy. The relationship between H pylori infection and chronic diarrhea without protein leakage remains controversial.An 8-month-old male infant presented to our hospital with severe watery diarrhea, erythema, and failure to thrive from approximately 1 month after birth. Blood, stool, esophagogastroduodenoscopy, total colonoscopy, and H pylori urease analysis results were positive, thereby suggesting atrophic gastritis.Atrophic gastritis and chronic diarrhea due to H pylori infection.We performed H pylori eradication therapy using triple therapy with vonoprazan (6 mg/kg), amoxicillin (300 mg/d), and clarithromycin (120 mg/kg) for 7 days.From approximately 1 week after the H pylori eradication therapy, the frequency of defecation had decreased, stool shape had improved, and body weight had gradually increased.H pylori infection can cause atrophic gastritis and chronic diarrhea even in infancy. Early eradication therapy for H pylori infection may be useful for prevention of gastric cancer and improvement in growth disorders.