Diabetes Insipidus and/or magnesium depletion
I've had this problem the entire 24 yrs. of my illness, and to some degree for many years before I got sick. Friends used to cal me "peanut bladder" because I could not sit all the way through a movie. One time I forced myself to sit all the way through a movie, and was in so much pain I could hardly walk to the bathroom. When I finally let loose, my pulse soared into the stratosphere and my friends had to take me to the emergency room, where they told me never to hold it like that again and if I had to hold it, to let it out in small amts., not all at once. This happened 11 years before I came down with FMS/CFS/Lyme and shows that my autonomic nervous system was already out of whack.
Both Dr. Teitlebaum (FMS and CFS) and Dr. Klinghardt (LYME), among others, have written that we have mild diabetes insipidus, which has nothing to do with sugar diabetes. The brain does not produce enough anti-diuretic hormone (ADH), in our case, due to hypothalmic-pituitary-adrenal axis supression. Sometimes aldosterone production is off too. I have two friends who've been tested for it, one with Lyme and one with CFS, and both tested positive. If you have this problem to any real degree, your electrolytes should be off in your regular lab work. Look at your last lab results and see if calcium, sodium or potassium are out of range.
Both of my friends took the preferred drug, desmopressin, and both got very ill from it. One did not pee for a whole day and stopped taking it. The other did not pee for over two days and started throwing up water, which can be fatal. Dr. Teitlebaum advises that the drugs are too strong for our milder version of this, and sugests we should just keep on "drinking like fish and peeing like racehorses". If you end up with a diagnosis of D.I., make sure you drink plenty of water and a Medic Alert bracelet or necklace is not a bad idea either.
Another clue to this is if you are asked to do a 24 hour urine collection test and require two jugs to do it, instead of the usual one jug. I messed up my first test because I did not realize I could not possibly fit a whole day's urine in one jug, even when depriving myself of water until I was so thirsty I could not sleep. I easily come close to filling two jugs when drinking normally for me.
I had a hair analysis done which showed a severe imbalance between calcium and magnesium. The lab knew nothing about my medical history but my age and name. The report said this imbalance would cause contraction of the bladder size and produce urinary frequency and urgency. It said I did not have deficiencies of either substance, just too much calcium relative to magnesium. I take a lot of oral magnesium, but in fbiro and esp. in Lyme (I don't know about CFS) the pathogen causes magensium to be excreted in the urine quite fast, so it must be constantly replenished throughout the day. You can test if this is your problem by peeing in a measuring cup several times and taking an average on the amount. I found that my usual bladder capacity is 1/2 cup. A normal person's is 2 cups. That explains why I pee 15-20 times daily, including 4-5 times at night. I stopped taking my calcium supps. but have seen no change.
So, I know a bit about possible causes, but am watching this thread to see if anyone has solutions. I have tried cranberry extract, which helps with the rare pain that feels like a UTI but isn't. It does not stop the frequency however. I spent two years on a low oxalate diet, which did not help at all.
Gracenote, your Azo sounds interesting, even though I do not have an acutal infection, but "AZO" says sulfa drug to me. Do you know if it is in the sulfa family? I am very allergic to those.
P.S. Knackered- because you are male, I would get the prostrate checked out, just to be sure it is not BPH (benign prostrate hypertrophy). Just because we have CFS, does not mean we can't still have mundane things like that too. My husband does not have CFS, FMS or Lyme, but he has BPH and always has to get up at night to pee because of it.