Which symptom is a classic presentation of a perforated peptic ulcer?

A classic presentation of a perforated peptic ulcer typically features an acute onset of epigastric pain. This is due to the sudden release of gastric contents into the peritoneal cavity, which causes irritation and inflammation of the peritoneum, also known as peritonitis. Patients often describe the pain as sharp or severe and it can radiate to the shoulders or back, which is indicative of referred pain due to diaphragmatic irritation.

In contrast, chronic heartburn and gradual abdominal discomfort are more commonly associated with less acute gastrointestinal issues, such as gastroesophageal reflux disease or various forms of gastritis, and do not typically suggest an emergency like a perforated ulcer. Severe constipation does not align with the symptoms of a perforated peptic ulcer either, as it is unrelated to the sudden abdominal pain and the acute clinical picture presented by a perforation.

Therefore, the acute onset of epigastric pain is a clear and specific symptom that aligns with the clinical presentation of this emergency surgical condition.