Morison's pouch is a anatomic location in the abdomen. I think it is important for you to have an open and frank discussion with your doctor.
Everyone has a Morison's pouch. However, this is a potential space. This means that it is empty in most people. When it fills and actually takes up space--there is often a problem. Fluid is the most common filler--and why it occurs can vary.
The actual location of this space is between the liver and the right kidney. It is inside the peritoneum (the inner lining of the abdomen).
This space can fill with fluid from a number of causes. One is abdominal trauma or bleeding
. Blood can pool there if there is internal damage. However, this is likely not the case for you if you are having problems for years. The other causes of fluid in the abdomen (also known as ascites) can be divided into three main categories. This can be caused by (A) heart problems like congestive heart failure (B) kidney problems like nephrotic syndrome or (C) liver problems like cirrhosis. Ovarian cancer is also a cause in women that should be ruled out.
The actual fluid there is not a problem--but what is causing the fluid is a problem. I encourage you to talk with your doctor.