Which of the following is an example of a surgical abdomen?

Pyloric stenosis is a condition that leads to gastric outlet obstruction due to the thickening of the pyloric muscle in infants. This condition requires surgical intervention to relieve the blockage, making it a clear example of a surgical abdomen. The signs of pyloric stenosis often include projectile vomiting and dehydration, and without surgical treatment, it can lead to serious complications.

In contrast, conditions like gastroenteritis are typically managed with fluid replacement and medical care but do not usually require surgery. The common cold and bronchitis are respiratory conditions that do not involve surgical intervention for resolution. Focusing on the need for surgical correction in cases of abdominal obstruction, pyloric stenosis stands out as the correct choice.