Frogs do have bladders, but I don't think there is such a thing as a "small bladder" in a frog. I suspect that the asker may be referring to the "gall bladder". If so, please see the related link below which shows a frog's gall bladder, below its liver.
near the back
B/t the lobes of liver is a rounded pouch gall bladder is located
The frog's urinary bladder is located in the lowest part of the body cavity.
the organ that is underneath the liver in a frog is the gall bladder
It is similar to the function of the gall bladder of a human. They both are used to store the bile, a digestive juice, that is created by the liver. When needed for digestion, the gall bladder secretes a small amount to aid in the breaking down of the food (specifically the emulsification of fats).
The frog's bladder functions to store urine produced by the kidneys before it is excreted from the body. It helps regulate the frog's water balance by retaining or releasing water as needed.
A couple of organs are located underneath the liver of a frog including the lungs, fat bodies, gull bladder, stomach, intestines, and depending on the gender, the eggs.
Um you could be a little more specific: color, size according to other organs, and position inside the frog. But still, I'm going to guess your either talking about the gall bladder or the urinary bladder. Here is what they look like and there purpose. Gall Bladder: It is the small green sack underneither the liver (looks like a booger... no joke). It's purpose is t store bile that is created by liver. The bile is secreted in small amounts and used to help digest food when a frog needs it. Urinary Bladder: If you look at the anatomy of a frog it would be the lowest organ in the frog. If disecting the frog it will be an empty sack. Its purpose is to store urine. I hope this helped! ^_^
The urinary bladder stores the urine in the frog.
It's how a frog "croaks" or makes it mating call.
The prostate is located at the base of the bladder and surrounds the first part of the urethra in the pelvis.
urinary bladder