There are provided a liquid preparation for oral administration which contains barium that is likely to be mixed with residues and is less likely to be precipitated in the intestinal tract, and a liquid preparation for oral administration and a composition for imaging a digestive tract which contain barium and enable the reduction of the dose of an intestinal tract cleaning solution in a the intestinal tract pretreatment. That is, there are provided an orally administered liquid preparation which contains barium and one or more types of thickening agents selected from the group consisting of a natural polysaccharide and a cellulose-based polymer, in which the viscosity at a shear rate of 21.54 s−1 is 100 mPa·s or greater and the viscosity at a shear rate of 464.1 s−1 is 5 mPa·s to 90 mPa·s, and the particle diameter D10 which is the particle diameter when the accumulation value in a volume cumulative distribution of the barium becomes 10% is 0.30 μm to 0.80 μm and the particle diameter D90 is 1.0 μm to 10 μm and a liquid preparation for oral administration used in CT colonography digestive tract imaging, which contains barium and a water-soluble polymer or a saline purgative agent, and is taken in an amount of 50 mL to 2000 mL all at once or in several parts over a period of time on the day before the CT colonography is performed.
