Green pears for good digestion

I wasn't eating much last April. Besides cooked rice, eggs, chicken nuggets, salted fish and bread, I only ate coleslaw. How minimal my food intake was. I eat green pears just because I like its taste, but then I realized it helped me flush my bowel content every morning without fail.

I have tried the yellow pear (Chinese white pear variety ya li 鸭梨) which is crunchier and succulent, and the red Bartlett which is softer, succulent and a lot sweeter, but these two do not give the same effect.