Hi welcome to Health care magic forum, You had gall bladder
operation 4 years back, and you are feeling the above said symptoms since 8months so it is clear that the symptoms are not due to operation but due to some thing else.
That could be amoebiasis
problem,late incissional hernia
or some thing else. It will be wise to consult a surgeon for diagnosis and treatment. You may need to have C.T.scan of abdomen , for confermation of the problem.
Besides i advise you to follow some diet recommendations as take much of drinking water. Take green leafy vegetables, and other fibre rich food.
Wishing for a quick recovery and thanks for calling.