What physical examination finding is indicative of pyloric stenosis in a 2-month-old?

The presence of a hard, moveable "olive-like mass" in the upper right quadrant is a classic physical examination finding associated with pyloric stenosis in infants. This condition involves the hypertrophy of the pyloric muscle, which leads to narrowing of the pylorus and obstructs the passage of food from the stomach into the duodenum.

As the condition progresses, the muscle becomes significantly thickened, and during physical examination, the hypertrophied muscle can often be palpated as a prominent mass in the upper right quadrant of the abdomen. The description of the mass as "olive-like" is commonly used in medical literature to help healthcare providers recognize this critical finding. Infants with pyloric stenosis often present with projectile vomiting after feeding and may exhibit dehydration or signs of electrolyte imbalances, but the palpable mass is the key physical sign that confirms the diagnosis.

This specific finding is crucial for differentiating pyloric stenosis from other causes of vomiting in infants. While the other options may indicate gastrointestinal distress or issues, they do not provide the definitive physical examination characteristic like the olive-shaped mass does in the context of pyloric stenosis.