Steamed bananas for constipation should be steamed for about 10-15 minutes. Banana for constipation is mainly for dry stools, to play the effect of ventilation and defecation, lubricating intestines and regulating intestinal tract. Bananas contain a lot of dietary fiber, most of which cannot be digested and absorbed, causing an increase in the amount of stool and promoting intestinal peristalsis. Bananas also contain a large amount of water-soluble plant fiber, which can promote the secretion of hypertonic gastrointestinal fluid, so that water is adsorbed to the dry stool, which plays a role in softening the stool and promoting its discharge. In addition, the pectin in bananas can regulate the gastrointestinal flora, promote the growth of beneficial bacteria and inhibit the growth of harmful bacteria, to achieve the role of regulating gastrointestinal function. But only ripe bananas have these effects, raw bananas may have the opposite effect, not only will not relieve constipation, but also aggravate constipation. Bananas should not be eaten on an empty stomach, otherwise it will lead to an increase in blood magnesium, inhibit the cardiovascular system, and may also cause numbness and drowsiness in the limbs.