Abdominal distension

IMO you need a medical checkup.

Fibroids

This may or may not help but I've found that quite a few things can cause it:

i) Lack of bowel movements ---> though you've mentioned that your family does not suffer from bowel problems and you eat a whole lot of fibre, you could still be getting a little bloat due to food remaining in your bowel. Basically if you are not eating large amounts it sticks around in there. Which is why you tend to crap well after a good curry.

ii) Pre-period bloat ---> Women tend to retain water and bloat around their period - (Just a theory) I know you mentioned the bloat was all the time.

iii) Beans, beans the musical fruit... ---> If you eat a whole lot of foods typically high in certain polysaccharides (especially oligosaccharides such as inulin) and include beans, lentils, dairy products, onions, garlic, scallions, leeks, radishes, sweet potatoes, cashews, oats, wheat, yeast in breads, and other vegetables, you can get bloated as they break down. Some fruits can also have this effect as they ferment.

iv) Stress and Anxiety ---> anxiety shuts down a part of the brain that handles digesting foods. Stress itself puts a great deal of pressure on your stomach and abdomen, and upsets hormone and neurotransmitter balance. That may create an environment where foods that could normally be digested easily end up being digested poorly, leading to the creation of gas and bloating. Also another point on anxiety - Hyperventilation (too much air in your system).

v) 'Obble Gobbling ---> Eating too fast can cause bloating.

vi) Eating Disorders ---> If you are bulimic or anorexic-bulimic, purging kinda bloats you. It gets worse when you eat more food later on in the day.

vii) Cortisol ---> You have lower levels of this hormone in your system at night and higher levels in the morning. It's also linked to the flight/fight response. If you have too much of this in your system due to being stressed often, then you could be in a state of *chronic stress* (where you body has gotten so used to being stressed that it is literally unable to relax) If you are unable to switch off and allow your body to go ahead with its relaxation response, how can you expect your bowel to relax and pass its contents naturally? Constant high amounts of this hormone can also lead to Increased abdominal fat.

viii) Lack of Sleep ---> Lack of sleep makes you stressed. MOAR CORTISOL

ix) IBS ---> You could have Irritable Bowel Syndrome - which is a pretty common cause of unexplained bloating. (I know you have already mentioned that you don't think you have this, but I may as well go all out with the post)

"Irritable bowel syndrome* (IBS) is a functional gastrointestinal (GI) disorder, meaning that the symptoms are caused by changes in how the GI tract works. The GI tract is a series of hollow organs joined in a long, twisting tube from the mouth to the *kitten*—the opening where stool leaves your body. Food is digested, or broken down, in the GI tract." http://digestive.niddk.nih.gov/ddiseases/pubs/ibs_ez/

x) err lactose intolerance? Though I'm not 100% on that one

xi) Malnutrition ---> Ever wondered why starving African children seem to have a bloated stomach? It's not just the dirty water or horrific lifestyle. A malnourished person may bloat due to an insufficient protein intake, despite a sufficient caloric intake.

xii) I think there's a few more reasons for it which are a bit more sinister, like ovarian cancer and coeliac disease.

Ways to combat the above:

1) Sleep more
2) De-stress (easier said than done)
3) Eat slowly
4) Eat larger amounts of bulky foods to pass stools
5) Do exercise as it helps to keep your system moving (though I know that you already have that one covered)
6) If you are bulimic or anorexic-bulimic: try not to purge.
7) If you are constipated, abdominal massages are a great way to slowly ease out the impaction. I find that lying on your stomach after this really helps. Also, get a yellow pages when you are on the bog and rest your feet on it. It's easier to go if you are in a squat-like position.
8) If you are suffering from malnutrition, consult your doctor.
9) Seek medical advice for any suspected conditions like IBS. It seems that there's a pill for everything these days.

other than that, I'm all out of possible causes

Try taking a probiotic pill. The amount in yogurt may not be enough.