Provided are aqueous solutions comprising polyethylene glycol (PEG) and electrolytes. A preferred aqueous solution comprises: (a) 350 to 600g/L PEG having an average molecular weight of 2500 to 4500 Da; (b) 8.0 to 20 g/L sodium chloride; (c) 1.0 to 3.0 g/L potassium chloride and (d) 3.0 to 11 g/L sodium bicarbonate. The solution may be substantially free of preservative. The solutions are useful for treating constipation and/or faecal impaction without requiring further dilution.