Normal or abnormal (Excess bile vs normal amount, abnormally appearing duodenal mucosa vs normal mucosa)

A 68-year-old man presented to our hospital with dysphagia due to food impaction. The patient gave a history of liver transplantation four years ago, regular sclerotherapy for esophageal varices, and food impaction {multiple times (a total of 5 with endotherapy each time)}. The patient underwent upper digestive endoscopy. The scope revealed an excess amount of bile in the bulb and second part of the duodenum. The presence of this excess amount of bile in the duodenum gives the mucosa a characteristic appearance with prominent duodenal villi# (natural chromoendoscopy).

NOTES:

1- Villi may be longer, especially in temperate areas.

2- In this case, no any complaint related to the duodenum, do we should biopsy or not?

3- are these elongated villi or healthy villi?

4-Is any amount of bile in the duodenum considered normal?

5- What is the condition with elongated villi?

6- Can we use bile as a dye for chromoendoscopy?