What is one sign that may indicate a child is suffering from pyloric stenosis?

Forceful vomiting is a classic sign of pyloric stenosis, a condition in which the pylorus (the opening from the stomach to the small intestine) becomes narrowed, obstructing the passage of food. This condition typically affects infants and is characterized by the infant vomiting forcefully, often described as "projectile" vomiting. This forceful ejection occurs because the stomach contracts strongly to try to push food through the narrowed pylorus, leading to the abrupt expulsion of stomach contents.

The timing of the vomiting usually occurs shortly after feeding, and it may happen several times a day, often resulting in dehydration and electrolyte imbalances in the child. This symptom, combined with other physical findings such as a palpable "olive" mass in the abdomen, can help healthcare providers diagnose pyloric stenosis.

In contrast to forceful vomiting, slow weight gain, frequent diarrhea, and unusual irritability may occur in various conditions but are not indicative of pyloric stenosis specifically. They do not directly relate to the obstructive nature of pyloric stenosis, making forceful vomiting the most telling sign of this gastrointestinal issue in children.