Bananas are in a bit of a conundrum, being known by some to cause constipation while others swear bananas cure constipation!
You see, when you eat bananas before they are fully ripe, that is, when they still have a greenish shading, you are not eating the ripe fruit. Instead you're eating it at a stage when it contains a lot of starch. This is what may cause bloating and constipation.
Another thing about bananas is their high fiber content. A medium sized banana can contain 3g of fiber. Although this is only 10% of the recommended daily amount for fiber, it is still high compared to most foods. the problem comes in when you consume too many bananas and too little water. The fiber in the bananas ends up hardening your stool and blocking your intestines, creating constipation. But if you eat ripe bananas and make sure you get enough water, then bananas will actually stimulate bowel movement and cure constipation! Confusing? Not at all!
Bananas also contain large about of pectin. Pectin has binding abilities and it contributes to binding the stool. It pulls out water molecules from the intestinal tract leading to rock hard stools that are hard to pass and cause constipation.
Many times, your constipation may actually be due to other poor dietary habits such as lack of wholesome foods, overeating, too many refined factory made foods and too little water.