The presence of 'irritation' that could be caused by certain types of chemicals produced by cells within the tissues of the small intestine. They might also be checking for indications of celiac disease. The physical 'look' of the tissue will also be checked - irritation could indicate acid is not being buffered as it flows from the stomach to the SI, suggesting too much acid release/GERD. There are many things they could be checking. The best person to ask this question of is your doc.
He could be looking for for different gi bugs like gastritis that may cause the inflammation and can be treated with medicines there are all sorts of things people usually assume cancer when they hear the word biopsy that's not always the case they did that to me and found out I had h-pylori which was fixed with very strong and expensive antibiotics. Here's a tip if that is what you have and you have to take that antibiotic pack because it's several pills you take everyday make SURE to eat lots of yogurt they atb were so strong that i took i actually ended up with thrush in my mouth good look let me know how it goes