Well, this will be working perfectly if you eat those already riped bananas. If you ate the unripe one, your constipation will be even more serious than before.
Why? Most of the riped bananas enriched with fiber that cannot be easily digested by ilium. In addition to that, these fiber soluble fruit fiber will absorb and spread the water inside our colon back to the feces.
However, you have to remember that only the Riped bananas and never ever consume those unripe bananas, or you will get yourself in the constipation trouble.
PS: Photo credits goes to arikuncoro.