The present invention, liquid for oral administration, which can without prolonging time required for the pretreatment and also without sacrificing the accuracy of inspection, it is possible to reduce the dose of the intestinal washing liquid in the bowel preparation, to reduce the burden of the subject , and to provide a GI composition used in the preparation of the liquid for oral administration. That is, a liquid for oral administration in the gastrointestinal tract contrast of CT colonography, and iodine containing compound and a saline cathartic or water-soluble polymer, the day before the CT colonography, once or more than once a 300~1200mL liquid for oral administration, which is characterized in that it is taken separately, and, contains the iodine compound, and a saline cathartic or water-soluble polymer, dissolved in water, iodine content 3.5~90mg / mL as an aqueous solution, the day before CT colonography, to provide a GI composition is characterized in that at one time or be taken at a plurality of times the 300~1200mL.本発明は、検査精度を犠牲にせず、また前処置に要する時間を長期化することなく、腸管前処置における腸管洗浄液の服用量を低減し、被験者の負担を少なくすることができる経口投与用液剤、及び当該経口投与用液剤の調製に用いられる消化管造影用組成物を提供する。すなわち、CTコロノグラフィの消化管造影における経口投与用液剤であって、ヨード化合物と、水溶性高分子又は塩類下剤とを含有し、CTコロノグラフィの前日に、300~1200mLを1回で又は複数回に分けて服用されることを特徴とする経口投与用液剤、並びに、ヨード化合物と、水溶性高分子又は塩類下剤とを含有し、水に溶解させて、ヨード含有量が3.5~90mg/mLの水溶液として、CTコロノグラフィの前日に、300~1200mLを1回で又は複数回に分けて服用されることを特徴とする消化管造影用組成物を提供する。
