y an amazing coincidence, when the new book by the T&A's resident doctor Tom Smith landed on my desk, it fell open on the entry "why do I keep gathering blue fluff in my navel?"

Now this is a question that has been exercising mankind - well, me anyway - since time immemorial. And the answer is not good news, particularly if you're reading this over one of your weekend meals.

Apparently, your belly button fills over the years with bits of skin, sweat, clothing and soap, which can set as hard as stone. Sometimes you can get an infection, particularly one called Pseudomonas pyocyaneus. Which is blue. So now you know.

Dr Tom's book is full of these fascinating nuggets of information, many of them based on questions put to him over the years by the readers of this very newspaper.

As Tom says in his introduction: "Most of the questions I received from readers are fairly predictable, even dull, but many are, shall we say, unusual.

"They are the sort that can't be answered by looking up the journals, and wouldn't be asked in a routine surgery appointment."

They include, says Tom, the sort of questions he's asked at social functions, often at dinner parties. So spare a thought for our very own Dr Tom as he's about to tuck into his starter and someone leans over and whispers: "Why does asparagus make my wee smell?"

Doctor, Have You Got a Minute? really is a volume of all the things that you really wanted to know about the workings of your body, but were either too embarrassed to ask or couldn't get them past your company's internet security firewall to find out on the web.

Written in an easy, often humorous, but never condescending or patronising manner, the book is perfect for dipping in and out of, and might well become the literature of choice by the side of many toilets up and down the nation.

It also restores faith in the health service, to some extent, especially for anyone who feels that the modern NHS just doesn't provide the kind of environment where you can pop into your local GP's surgery and ask him about things that might seem inconsequential but have been worrying you.

Dr Tom's bedside manner in the book brings to mind a golden age of family medicine, one that many of us will be too young to recall and which some will believe only exists in TV period pieces such as Dr Finlay's Casebook.

Dr Tom appears to be the GP that everyone would wish for, who'll give you no-nonsense advice and answer your questions with a twinkle in his eye, never making you feel stupid for wondering why one of your two veg hangs lower than the other one.

Of course, Dr Tom wouldn't want anyone to take his word as total medical gospel; the book is primarily for entertainment value.

He says: "If you are seriously worried about something, you should visit your own GP. Here I merely offer some of the commonest, and oddest, questions that I have been asked over the years."

Sound advice, and while he does insist that his comments, although accurate, are "off the cuff" and not written with reference to medical texts, it has to be said that if laughter is indeed the best medicine, then a copy of this book to be taken at regular intervals throughout the day should lift any spirits.

l Doctor, Have You Got a Minute?, by Dr Tom Smith, is published in hardback by Short Books priced £9.99.