Differential Diagnosis for a 7-Month-Old Boy with Persistent Bilious Vomiting
- Single Most Likely Diagnosis
- Intussusception: This condition is characterized by the telescoping of one portion of the intestine into another, leading to bowel obstruction. It is a common cause of intestinal obstruction in infants and is consistent with the symptoms of bilious vomiting, abdominal distension, and hypertympanic abdomen. The absence of bowel sounds and the infant's distress upon abdominal palpation further support this diagnosis.
- Other Likely Diagnoses
- Pyloric stenosis: Although typically presenting with non-bilious vomiting, pyloric stenosis can sometimes cause bilious vomiting if the obstruction is incomplete or if there is associated intestinal obstruction. However, the absence of a palpable "olive" and the presence of bilious vomiting make this less likely.
- Incarcerated inguinal hernia: An incarcerated hernia can cause bowel obstruction, leading to bilious vomiting, abdominal distension, and tenderness. The history and physical examination should be carefully evaluated for signs of a hernia.
- Volvulus: A volvulus refers to the twisting of a portion of the intestine, which can cause bowel obstruction and ischemia. The symptoms of bilious vomiting, abdominal distension, and tenderness are consistent with this diagnosis.
- Do Not Miss Diagnoses
- Midgut volvulus: This is a life-threatening condition that requires prompt diagnosis and treatment. It typically presents with bilious vomiting, abdominal distension, and tenderness. The risk of intestinal ischemia and necrosis makes it a critical diagnosis not to miss.
- Necrotizing enterocolitis: Although more common in premature infants, necrotizing enterocolitis can occur in term infants and is a life-threatening condition. The presence of bilious vomiting, abdominal distension, and tenderness, along with signs of sepsis, should raise suspicion for this diagnosis.
- Rare Diagnoses
- Hirschsprung's disease: This congenital condition is characterized by the absence of ganglion cells in the distal bowel, leading to chronic constipation and intestinal obstruction. Although it typically presents in the neonatal period, it can sometimes be diagnosed later in infancy.
- Meconium ileus: This condition is characterized by the obstruction of the small intestine due to impaction of meconium and is often associated with cystic fibrosis. The presence of bilious vomiting and abdominal distension in a newborn or young infant should raise suspicion for this diagnosis.