Gastroesophageal Reflux Disease (GERD): This condition is common in infants and can cause gastric bleeding due to the reflux of stomach acid into the esophagus, leading to irritation and potential bleeding.

Milk Protein Allergy: An allergy to milk proteins can cause inflammation and bleeding in the gastrointestinal tract of infants.
Infection (e.g., Helicobacter pylori): Although less common in infants, infections can cause gastric bleeding.
Swallowed Maternal Blood: Infants may swallow blood during delivery or from cracked nipples during breastfeeding, which can be mistaken for gastric bleeding.

Volvulus or Intussusception: These conditions involve the twisting or telescoping of intestinal segments, which can lead to ischemia and bleeding. They are medical emergencies that require prompt diagnosis and treatment.
Hemorrhagic Disease of the Newborn: A condition caused by vitamin K deficiency, which can lead to bleeding due to coagulopathy.
Trauma or Child Abuse: Accidental or non-accidental trauma can cause gastric bleeding and must be considered, especially if other signs of abuse are present.

Congenital Anomalies (e.g., gastric duplication, Meckel's diverticulum): These rare conditions can cause gastric bleeding in infants.
Inherited Coagulopathies (e.g., hemophilia): Although rare, these conditions can cause bleeding due to coagulation factor deficiencies.
Tumors (e.g., gastric teratoma): Extremely rare in infants, but can cause gastric bleeding if present.