Allergic colitis: This condition is a common cause of occult blood in stools in infants, often associated with cow's milk protein allergy. It leads to inflammation and microscopic bleeding in the colon.

Anal fissure: A tear in the anal mucosa can cause pain and bleeding during bowel movements, leading to occult blood in stools.
Gastroesophageal reflux disease (GERD): Although more commonly associated with vomiting and irritability, GERD can also lead to occult blood in stools due to esophageal or gastric mucosal injury.
Infectious colitis: Bacterial or viral infections can cause inflammation and bleeding in the colon, resulting in occult blood in stools.

Intussusception: A condition where a part of the intestine telescopes into another, leading to bowel obstruction and potentially life-threatening complications if not promptly diagnosed and treated.
Meckel's diverticulum: A congenital anomaly of the small intestine that can cause bleeding due to the presence of ectopic gastric mucosa.
Hirschsprung's disease: A congenital condition characterized by the absence of ganglion cells in the distal bowel, leading to obstruction and potentially enterocolitis, which can cause occult blood in stools.

Juvenile polyps: Benign growths in the colon that can cause bleeding, although rare in infants.
Inflammatory bowel disease (IBD): Conditions like Crohn's disease and ulcerative colitis are rare in infants but can cause occult blood in stools due to chronic inflammation of the gastrointestinal tract.
Vascular malformations: Abnormalities in blood vessels, such as hemangiomas, can cause bleeding in the gastrointestinal tract, although this is a rare cause of occult blood in stools in infants.