How is the duodenal mucosa in functional dyspepsia?

Gastric mucosa has been widely studied during the pre/post-Helicobacter pylori (Hp) era. Excluding peptic ulcer disease (PUD), the duodenal mucosa has not been thoroughly analyzed, even less so in functional dyspepsia (FD). We would like to make some comments after studying 161 dyspeptic patients with samples taken from the gastric body, antrum, proximal and distal duodenum.