The invention provides a colon cleansing solution comprising:a) 300 to 800 mmol per litre ascorbate anion provided by a mixture of:(i) ascorbic acid and(ii) one or more salts of ascorbic acidthe components (i) and (ii) being present in a molar ration of from 1:4.5 to 1:7.0; andb) 10 to 200 g per litre polyethylene glycol.The invention also provides methods and kits associated with, or making use of the solutions, and compositions for the preparation of the solutions.本發明提供一種結腸清潔溶液,其包含:a)300至800毫莫耳/公升由以下各者之混合物提供之抗壞血酸根陰離子:(i)抗壞血酸及(ii)一或多種抗壞血酸鹽,該等組分(i)及(ii)以1:4.5至1:7.0之莫耳比存在;及b)10至200公克/公升聚乙二醇。本發明亦提供與該等溶液相關或使用其之方法及套組,及用於製備該等溶液之組成物。