A female patient of mine who has been transformed by allergy management still had an irritable bladder. Then she read a newspaper cutting about a link between fluoride and frequent urination at night. The result has been dramatic relief of urgency, irritation and frequent night time trips to the toilet. Dr M J Radcliffe, Marchwood, Southampton......Dear Dr Radcliffe: Thank you for sending in the cutting, which told of a reader who was awakened repeatedly at night by the need to urinate. Here's what it said, readers: "My GP said there was no prostate problem and became very puzzled. By a coincidence, I discovered that fluoride has a diuretic effect. I switched to a fluoride free toothpaste and my problems cleared. My young nephew suffered from chronic bedwetting, but eight weeks after he was taken off fluoride, his symptom disappeared." Perhaps kiddy fluoride toothpaste and drops should be the first suspect when a child wets his bed. (See also new evidence against fluoride, p 11).