What condition should a nurse suspect in a 4-week-old infant with rapid onset of abdominal distention, vomiting, bloody stools, and signs of shock?

The presence of rapid onset abdominal distention, vomiting, bloody stools, and signs of shock in a 4-week-old infant strongly indicates necrotizing enterocolitis (NEC). This condition is characterized by inflammation and necrosis of the intestinal wall, which is particularly common in premature infants or those with low birth weight.

NEC typically presents with the symptoms observed: abdominal distention due to gas accumulation in the intestines, vomiting from bowel obstruction or irritation, and bloody stools resulting from the damaged intestinal lining. Additionally, signs of shock, such as decreased perfusion or lethargy, further support the diagnosis, as the necrotic bowel can lead to sepsis or systemic complications that compromise hemodynamic stability.

Other conditions listed do not align as closely with the collection of symptoms. For instance, intestinal obstruction can present similarly but is less characteristic of bloody stools in a young infant unless there has been significant constriction. Appendicitis is not common in infants this young and typically presents with a different symptom profile. Gastroesophageal reflux would not typically cause bloody stools or shock and would present more with feeding difficulties or discomfort rather than the acute symptoms described.

Thus, the acute combination of symptoms described points to necrotizing enterocolitis