Duodenal Ulcer Common Sites: Understanding Location and Implications

Duodenal ulcers most commonly occur in the duodenal bulb, accounting for 90% or more of all cases. Anatomically, the digestive tract follows a sequence starting from the esophagus to the stomach, then through the pylorus, which directly connects to the duodenal bulb. The junction between the bulb and the descending portion is known as the bulb-descending junction, followed by the descending part and the horizontal segment of the duodenum.

Symptoms and Anatomical Relevance

Due to its anatomical location, pain from a duodenal ulcer often manifests below the xiphoid process or slightly to the right of it. This localization is primarily due to irritation or inflammation in the duodenal bulb, which is the most frequent site for ulcer formation.

Unusual Locations and Potential Causes

If an ulcer is detected in less common areas such as the bulb-descending junction, descending portion, or horizontal segment during endoscopy, further investigation is warranted. These atypical locations may suggest underlying conditions, such as a pancreatic neuroendocrine tumor, which can lead to ulcer formation in the duodenum.

Role of H. pylori in Ulcer Development

It's important to note that approximately 80% of duodenal ulcers are linked to Helicobacter pylori infection. In most of these cases, the ulcers are located in the duodenal bulb, reinforcing the correlation between this bacterial infection and ulcer development in typical locations.