DD is 21 and for the past 7 years has suffered infections causing severe abdominal pain, vomiting, raised temperature and tenderness. She has had one scan and is shortly to have another. No cause found but medics have suggested the possibility of cystitis, 'bad luck', stricture of urinary tract due to scarring... Any suggestions of foods/liquids that would either be beneficial or best avoided other than avoiding alcohol, citrus fruits and spicy food gratefully received. She has been advised that cranberry juice is a good choice but not juice drink because of the high sugar content. DD is 5ft 3" and weighs 57 kilos (mixed systems, sorry).