Differential Diagnosis for a 1-Month-Old Boy with Blood-Streaked Stools
- Single Most Likely Diagnosis
- Allergic proctocolitis: This condition is a common cause of blood-streaked stools in infants, especially those who are breastfed. The recent introduction of antibiotics to the mother could have altered the infant's gut flora, potentially triggering an allergic reaction. The presence of blood and mucus in the stool, along with the otherwise healthy appearance of the infant, supports this diagnosis.
- Other Likely Diagnoses
- Infectious gastroenteritis: Although the infant appears well, a viral or bacterial infection could still be the cause of the blood-streaked stools. The recent course of antibiotics taken by the mother could have increased the risk of an imbalance in the infant's gut flora, making them more susceptible to infection.
- Anal fissure: Despite the absence of noted fissures on anal examination, it is possible that a small, undetected fissure could be causing the blood-streaked stools. This diagnosis should still be considered, especially if the infant shows signs of pain during defecation.
- Do Not Miss Diagnoses
- Intussusception: Although less common in infants as young as 1 month, intussusception is a life-threatening condition that requires prompt diagnosis and treatment. The presence of blood and mucus in the stool, along with abdominal distension or tenderness, could indicate intussusception.
- Hirschsprung's disease: This congenital condition can cause obstructive symptoms, including bloody stools. Although the infant's weight and length are tracking normally, Hirschsprung's disease should still be considered, especially if the infant shows signs of abdominal distension or failure to thrive.
- Rare Diagnoses
- Cow's milk protein allergy: Although the infant is breastfed, it is possible that the mother's diet contains cow's milk protein, which could be passed to the infant through breast milk, causing an allergic reaction.
- Inflammatory bowel disease: This condition is rare in infants, but it should still be considered, especially if the infant shows signs of failure to thrive, abdominal pain, or persistent bloody stools despite treatment for other conditions.