roughage

详细解释:n. 粗饲料, 粗粮
【医】 粗糙食物

英语解释：

名词 roughage:

coarse food high in fiber but low in nutrients; its bulk stimulates peristalsis

例句：

If you're constipated you should eat more roughage.假若便秘就应该多吃粗糙食物。