Breaking it down...
Focal = a spot, not all over. Chronic = constant, not once-in-a-while.
Peptic-type = damaged by exposure to stomach acid. Duodenitis = inflammation
/damage of duodenum, the very beginning of the small intestine that actually connects to the end of your stomach. H. Pylori negative = it was not associated with a bacterial infection that is well known to cause ulcers. Hope that is helpful.