Thickened gall bladder wall is a sign of Cholecystitis (inflammation of the gall bladder. Infection of the gallbladder is the most common cause of this. Even if there is no gall stone/calculus, you need to be thoroughly evaluated by a specialist laparoscopic surgeon. Depending on symptoms, clinical examination and blood investigations, you will need the appropriate treatment. Surgery may also be needed if it doesn’t resolve by medications.