A Distended abdomen (otherwise known as Bloating) can be caused by several different things:
1/ Distended tummy - can be caused by food intolerances, water retention, or stress, or bad eating habits.
Solution - Try eliminating foods one at a time to find out what your 'problem food' may be.
2/ Gas - is so often caused simply by bad eating habits. Check how often you chew when you eat? You should chew each mouthful at least 10 times for it to be broken down well for the stomach to digest it.
Solution - Also eating slowly helps you to not swallow air when eating. Eat less fermented foods, excess bad bacteria in the gut.
3/ Pain in Tummy - if you have not already seen your G.P Please do so to rule out any structural issues. The pain can also be diagnosed as I.B.S which is a functional ailment rather than structural. Your bowels can be inflamed or torn - so causing pain.
Solution - Generally Candida is very common with sufferers of IBS and should be ruled out first.
4/ Constipation or Diarrhoea - bloating can be a symptom of constipation. Generally speaking, everyone should go to the loo about 2 hours after every main meal. Yes, I do mean 2 to 3 times a day instead of from time to time over a week.
Solution - Eat less protein rich foods; mix meat with salads to provide roughage to clear the gut instead of carbs; replace some meats/fish with raw, unsalted nuts. Diarrhoea can be caused by bacterial infection, lactose or other food intolerance, any medication you are taking.