Gallbladder size: is it affected by the oral intake of water or dilute contrast medium?

Examinations of the gallbladder are performed by ultrasonography while patients are in a fasting state. In contrast, computed tomography of the abdomen is carried out in fasting patients who were given 2% meglumine diatrizoate (Urografin) solution to opacify the gut. Sonographic examination was performed to establish whether the weight of fluids given to patients had any effect on the volume of the gallbladder. Gallbladder size was measured in subjects with a normal gallbladder. The gallbladder also was measured in 117 people in the fasting state, and 10 and 30 minutes later, it was measured again after an intake of 500 ml of water or a dilute solution of contrast medium. Both groups showed evidence of gallbladder contraction, but no significant statistical difference between them was apparent. It appears, therefore, that the contrast medium solution given before abdominal computed tomography may cause some gallbladder contraction.