There's another possiblility: adrenal issues.

From: http://www.doctorbuxton.com/svc_adrenal.php4

Other symptoms can occur when the adrenals are not functioning properly. Because the level of aldosterone can also drop in adrenal fatigue, some patients suffer from increasing thirst and a sense of constant dehydration. They complain that they have weak or hyperactive bladders that need to be emptied more and more often. They may also develop a tendency to get lightheaded or weak at times. This is because with less aldosterone, the kidneys will excrete water from the body faster and this leads to increased urination, lowered blood pressure, and increased thirst.

Frequent nighttime waking to urinate can also be a symptom of sleep apnea.

From Steven Park's (apnea doc's) website:

We’ve know for many years that frequent bathroom trips at night are not due to bladder or prostate problems, but mostly due to breathing pauses that make you wake up and and think that you have to go. Numerous studies have shown that most men and women who have to go to the bathroom often at night or have overactive bladders during the day actually have sleep apnea.

A new study confirms these findings again, but points out that the presence of frequent trips to the bathroom is as sensitive in predicting obstructive sleep apnea as snoring!

Sleep apnea also makes the body produce more urine, and because you wake up every few hours, you’ll want to go, but you won’t have a completely full bladder. Sudden shifts in blood flow into the heart after an obstructive event increases production of atrial natriuretic peptide, which makes you produce more urine. One study found that diluted levels of urine during these episodes is also predictive of having obstructive sleep apnea.

Links to studies found here: http://doctorstevenpark.com/sleep-apnea-and-nighttime-urination

I had exactly the same problem a few years ago, and tried the liquid avoidance thing such as yourself to no avail; so I took the step of having a chat with my GP.

After checking it wasn't a prostate problem [you may wish to set your mind at rest here as well - I'm the same age as you and he said it wasn't uncommon for things to manifest that early] he placed me on some low level diuretics [Furosemide in the UK] to take at 5pm to ensure my bladder was empty by the time I went to bed. I only sipped water after that time if I needed liquid.

This all worked perfectly, but being on pharmaceutical drugs long-term didn't appeal, so I switched to a herbal product [Aqua-ban] throughout the day, and swapped my afternoon green tea to dandelion - a natural diuretic.

This used to happen to me when I was overtraining and/or undereating and had other cortisol issues. I'm almost positive that that's what this is, for many people. Get cortisol things in check. That completely 100% solved it for me. I never get up to pee in the middle of the night.

Although your other issues with urination are interesting so you might want to see a doctor. Could be the prostate. But in general, for most people, what I said above ^ I strongly believe.

I find high protein to be quite diuretic and increases the amount of water I need to drink/extrete, so you may want to try reducing protein intake, especially before bed.

Stricter paleo definitely helped me. Also helpful, even though it is taken with water!, has been Natural Calm (i.e. Magnesium). I started taking it at night becasue Robb Wolf and other Paleos seem to feel it's generally important because of soil depletion. It had this happy side effect.

Between stricter paleo and Mg, I'm down from 2-3 per night to basically zero.

I've had a similar problem for as long as I can remember. I wake-up multiple times during the night/early morning to urinate. I often wondered how much sleep I actually got during the night.

Recently, I have started taking 2 capsules of ZMA before bed. Not only does it help make me drowsy enough to fall asleep, I don't recall ever getting up in the middle of the night to go to the bathroom. I've tried melatonin many times in the past, but that never keeps me asleep through the night and I often wake up to go to the bathroom even when I take that.

I strongly recommend ZMA!

Increasing natural melatonin production, by improving sleep hygiene (Black out curtains, eye mask, no caffiene, alcohol) or using Flux Softeware on all LED digital dsplays enables a reudction in urine production and greater relaxation of bladder walls. Hence the lower production of urine combined with increased capacity due to relaxation of bladder wall muscles obviates the need for nightly visits to the loo.

You may find the use of TIME RELEASE MELATONIN supplements creates the same benefits. Start with the lowest dose you can find and work up slowly. Expect more vivid dreaming while you get used to melatonin, Enjoy it while you can it doesn't last.

May I also suggest to those who still feel the need for nightly walkabouts to the the loo, they invest in stick on lights with movements sensors. These can be stuck low down the wall on route to the loo so no light shines directly in the eyes to stop melatonin production, so you are better able to sleep on return to bed.

I think I also have low sized bladder - I have to "get up" about 3 / 4 times per night - and have had to since teens. But I long since learned just to go straight back to sleep.

Also have to go a lot during the day - partly due, I know, to drinking lots of water, tea, water kefir and wine. But if I don't have a big liquid intake I worry about dehydrating!

You can get a nifty glass urinal at the Swiss Military Megastore for only 2 francs. I wonder if the US Army Surplus has a similar contraption? Doesn't deal with the urge itself, but does solve the "getting up" issue, and you can stash it under the bed betweentimes. Makes a good 65th birthday gift for your man, too.

I found taking saw palmeto extract to work at reducing night time visits to the can. It helps with the prostate somehow.

I don't think I've ever made it through the night without getting up to urinate at least once. This is normal for females at least. And yes, I often have dreams about searching for a toilet or finding one and not being able to go. It's awful! I finally decided that I needed to concentrate on ways to fall back to sleep easily instead of depriving myself of liquid or taking drugs. The thing that has helped me most is not to turn on the lights (I mean no lights!). Not checking the time and not talking also help. If I can stay in that "half-sleep, half-groggy" stage, I usually fall right back to sleep.

Forgive me if this has been mentioned in another answer (I didn't see it) but are you low-carb or moderate-carb? How long have you been eating this way?

I ask because (for me, at least) during the "induction" of low-carb, when you are entering Ketosis and adjusting to more fat and water in the diet - It's fairly common to get up to pee at night and the urgency is fairly rapid as well.

This subsides about 1-2 weeks later, well, it did for me anyway. And I still drink a massive glass of water before bed.

You should go to a doctor and have your prostate checked to rule out this possibility. Since you already have bladder issues I also suggest you take a prostate health supplement. One that would provide nutrients that are prostate specific. Read a few Super Beta Prostate testimonials to find out more, if you're interested.

You should up your salt intake. I think the salt and dehydration paranoias are a bad combination for nighttime uniration.

I didn't realize this should be considered a problem. I get up around 4 a.m. every morning and take a toilet break. Just one of the things I do.

This may not sound like an expert but have you tried natural prostate supplements? I've read Super Beta Prostate testimonials and found that they actually do work for men in developing a healthy prostate.