• A. 1st part of duodenum ✓
  • B. 2nd part of duodenum
  • C. Distal 1/3rd of stomach
  • D. Pylorus of stomach


Peptic ulcers are open sores that develop on the inside lining of the stomach (gastric ulcers) or the upper part of the small intestine (duodenal ulcers). The majority of peptic ulcers occur in the duodenum, particularly in the first part of the duodenum, rather than in other parts of the digestive system.

Peptic ulcers are commonly caused by infection with Helicobacter pylori bacteria or by long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs). The acidic digestive juices in the stomach and duodenum can also contribute to the development of peptic ulcers by damaging the protective lining of these organs.

The first part of the duodenum is more susceptible to peptic ulcers due to its exposure to gastric acid and pepsin, which are secreted by the stomach. Additionally, this area is where partially digested food mixes with stomach acid before entering the small intestine for further digestion and absorption. The combination of these factors makes the first part of the duodenum a common site for peptic ulcer formation.