Sorry for not posting back right away. I've been sick.
First off, just in case anybody else has been following the post, I got an answer to my question from the hospital, who will be doing the test properly in a fortnight.
The answer is that yes, you do have to eat more choline-rich foods before the test to get a positive result, and you should actually do this 24 hours before. So I did start eating high choline foods a little bit too late. The hospital sent through a list of things to binge on before the tests, including all the usual suspects - eggs, fish etc, and also some things like broccoli etc, which I guess exacerbate the symptoms. Anyway, hope that's useful to people in future - eat high-choline foods during the 24 hour period before you have a urine test!
To answer some of your questions:
-No, it's not a fish smell, it is more amoniacal, although it has been described to me at various stages as more like garlic, onions and other things - all of which I gather are actually more common with tmau.
-Yes, I am always aware of the odor. Thank god. I can't think of anything worse than not knowing what it is that everybody else can smell and is being rude to you about. I have the deepest sympathy for trimethylaminuria sufferers who have just "got used to it" over the years.
-I don't know anything about the genetics of tmau that are specific to the condition. I am only going on what I learned in biology at school, which was quite a long time ago, obviously! Anyway, what I do remember are the basic principals of genetic inheritance. If a gene is very recessive (and I'm assuming that as tmau is so rare, there won't be any genes more recessive than it!) then you have to inherit it from both parents. There was a 50% chance of getting it from my mother, as I am female and she has two x chromosomes. However, my father obviously also carries it on the x chromosome, as he is not a sufferer, but has passed it on to me as a female. As my sister is also (obviously) female, she must have inherited the same x chromosome, but obviously got a different one from my mother, as she doesn't have symptoms. Ergo, she is a carrier and my brother has a 50% chance of being one. I've explained it poorly, but I've found this website, which might be clearer:
http://www.accessexcellence.org/RC/VL/GG/recessive.php.
Obviously this means nothing if it turns out not to be genetic (fingers crossed!)
I haven't done any
colonics etc, although I had always meant to try it out, as in the back of my mind I thought it was likely to work. Now that I know about tmau and what it is, I will definitely be giving it a try!
Thanks for the info about the bacteria that excrete ammonia. I hadn't thought of that, but will definitely look into it some more. I doubt my doctors do know about it, otherwise they would have suggested it on the numerous times I went to them and they laughed in my face. Also, I have had tests for various bacteria in the gut a couple of times when I got food poisoning abroad, and they didn't mention it, but that was probably because they were testing for the wrong kinds of bacteria(??) Do you know anything about the tests for that? If not I will do some research on my own.
FYI, the doctors are pretty much the only ones that don't believe me. It seems to be their general attitude to anything that's not in their most basic textbooks. All of my friends know that there is something wrong with me - and a lot of horrible colleagues who couldn't care less about me as a person have made it quite clear that they know, too. The problem is that the horrible people always think it's your fault, don't they? Like anybody would chose to be this way.
Anyway, rant over.
Am grateful once again for your contribution to my little thread. As I said, I'll let you know what the test results say!
TM :)