A first colon cleansing solution comprising (i) 70 to 250 g per litre PEG having an average molecular weight of 2500 to 4500 Da. (ii) 2.0 to 20 g per litre of one or more alkali metal sulphates, alkaline earth metal sulphates or a mixture thereof (iii) optionally one or more electrolytes; (iv) optionally one or more flavouring agents; and (v) optionally one or more sweeteners. and a second 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 acid the components (i) and (ii) being present in a molar ratio of from 1:4.5 to 1:7.0; and b) 10 to 200 g per litre polyethylene glycol for use in a method of cleansing the colon of a subject before a diagnostic, therapeutic or surgical procedure comprising: - administering to the subject an effective amount of a first colon cleansing solution; - administering to the subject an effective amount of a second colon cleansing solution, whereby the first colon cleansing solution is taken over a time period t followed by optional additional clear fluid over a time period t(cfl), and then following a time interval t(dose interval), the second colon cleansing solution is taken over a time period t followed by optional additional clear fluid over a time period t, whereby the subject undergoes the surgical, therapeutic or diagnostic procedure at a time t 2 after the beginning of the colon cleansing method, and whereby the time interval after the completion of the second additional clear fluid and the start of the surgical, therapeutic or diagnostic procedure is t(procedure interval). wherein the subject ingests the first and second cleansing solutions on the day of the diagnostic, therapeutic or surgical procedure, and: - t is 15 minutes to 1 hour (for example 30 minutes); - t is 15 minutes to 1 hour (for example 30 minutes), - t is 15 minutes to 1 hour (for example 30 minutes); - t is 15 minutes to 1 hour (for example 30 minutes); t 2 is in the range of from 4 to 10 hours; t(dose interval) is in the range of from 30 minutes to 4 hours; and t(procedure interval) is from 1 to 6 hours. (i) 70 to 250 g per litre PEG having an average molecular weight of 2500 to 4500 Da. (ii) 2.0 to 20 g per litre of one or more alkali metal sulphates, alkaline earth metal sulphates or a mixture thereof (iii) optionally one or more electrolytes; (iv) optionally one or more flavouring agents; and (v) optionally one or more sweeteners. 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 acid the components (i) and (ii) being present in a molar ratio of from 1:4.5 to 1:7.0; and (i) ascorbic acid and (ii) one or more salts of ascorbic acid b) 10 to 200 g per litre polyethylene glycol - administering to the subject an effective amount of a first colon cleansing solution; - administering to the subject an effective amount of a second colon cleansing solution, - t is 15 minutes to 1 hour (for example 30 minutes); - t is 15 minutes to 1 hour (for example 30 minutes), - t is 15 minutes to 1 hour (for example 30 minutes); - t is 15 minutes to 1 hour (for example 30 minutes);