Unripened, green bananas can make you constipated. These bananas are full of heavy starches, which can exacerbate constipation. On the other hand, a ripe banana, because of its fiber content, can help move the bowels through the intestinal tract so, in that respect, bananas are good for relieving constipation. 大家吃的应该都是熟香蕉吧. http://www.ehow.com/about_5398471_do-bananas-cause-constipation