A solution in water comprising the following components at the following concentrations: (a) N×(70 to 130) g/L polyethylene glycol (PEG) having an average molecular weight of 2500 to 4500; (b) N×(1.6 to 4.0) g/L sodium chloride; (c) N×(0.2 to 0.6) g/L potassium chloride; (d) N×(0.6 to 2.2) g/L sodium bicarbonate; (e) N×an amount of preservative; (f) optionally N x an amount of flavouring; and (g) optionally N×an amount of sweetener, where N is in the range of 2 to 8. The solution is a concentrate for dilution. In use it is diluted N-fold with water to provide a solution for administration to a subject for the treatment of constipation or faecal impaction. Also provided are solutions, kits, unit doses and methods that comprise or use the solutions.