Isolated Rectal Bleeding in Newborns : Allergic Proctocolitis or Neonatal Colitis Transient - COLON Study

Inclusion of all newborns in the neonatal medicine department at Nice University Hospital with isolated rectal bleeding. A note of information and non-opposition will be presented and given to the biological mother. She has the right to object to this study, on her own initiative, at any time. Collection of data relating to the newborn during hospitalization, the results of the clinical examination and the systematic check-up carried out in accordance with standard practice, and data at discharge. Follow-up of the newborn to determine the cause of rectal bleeding and therefore the frequency of procolitis allergic to cow's milk proteins. Prospective observational study of current practices without any intervention.