Disappointing? Sure. Embarrassing? Yes. But premature ejaculation, like flatulence, constipation and diarrhoea, may just be a part of life. The proof: a 1948 study by the noted biologist Alfred Kinsey revealed that a whopping 75 per cent of men ejaculate within two minutes of initiating sex, and within a minute or sometimes seconds after penetration. (Perhaps you can thank the adult-film industry for raising your expectations - and hers.)

Of course, that isn't to say you can't learn to master your own domain. You can. In fact, you will. And that goes for those other below-the-belt troubles as well. Whether a case of the trots leaves you perched on the porcelain throne or you're pumping out more gas than a herd of cows, we've uncovered scientific strategies to help you take back control of your body. The bonus: they won't hurt your ego, either.

30: percentage of sexually active men who complain they ejaculate prematurely

Why it happens
Explanations for premature ejaculation run from the biological (supersensitive skin on the penis) to the psychological (anxiety, guilt or inexperience). Most recently, it's thought that premature ejaculation is due to a combination of the two.

What to do

Schedule a prostate exam. Scientists in Italy and Egypt found that as many as 64 per cent of men with premature ejaculation also have an inflamed prostate.

Practise the "start-stop method". "It teaches you to better sense and delay your orgasm," says Dr Barry W. McCarthy, author of Coping with Premature Ejaculation. During intercourse, simply stop just before the point of no return, relax, and then start again. Studies show a success rate of up to 95 per cent using this technique.

Take a yoga class. Researchers in India found that men with premature ejaculation problems lasted three times longer during sex after 12 weeks of practising an hour of yoga daily. According to the scientists, classic yoga movements strengthen your pelvic muscles, and stronger muscles improve your control as you approach orgasm. Also, yoga breathing helps reduce anxiety.

10 to 14: number of times the average guy passes wind each day

Why it happens
When the bacteria in your colon break down fermentable fibres and undigested starches - primarily from plant foods such as beans, brussels sprouts, onions, celery, carrots, raisins, bananas, wheat germ and oats - the gas by-products take a back-door exit.

As for the stench, it comes specifically from three sulphur-containing gases: hydrogen sulphide, methanethiol and dimethyl sulphide, which have odours that scientists at the University of Minnesota in the US compare to "rotten eggs", "decomposing vegetables" and something "sweet", respectively. (Disgusting trivia: if you've ever wondered why flatulence varies in odour and intensity, it's simply determined by the mix of these gases. What's more, the researchers found that women's gas contains higher concentrations of hydrogen sulphide - and a worse odour - than men's.)

What to do

Try a gas-free diet for a week. That's how long it takes to find relief from a flatulent lifestyle, according to Spanish researchers. Simply avoid the foods listed above and eat mainly meat, fish, eggs and easy-to-digest carbohydrates, such as those in rice, gluten-free bread, tomatoes, lettuce, grapes and cherries. After a week, start reintroducing foods one by one until you identify the worst offenders. Then limit your diet as indicated.

Check labels for sugar alcohols. These sugar substitutes have been tweaked chemically so that they're not completely absorbed by your small intestine. The three you should watch out for are sorbitol, mannitol and maltitol, which are often found in protein shakes and sugar-free gum. In fact, less than 10 grams of sorbitol - the amount in a pack of sugar-free gum - is enough to increase your gas output and also increase the likelihood of diarrhoea.

If diet changes alone don't do the trick, try Blackmores' Digestive Aid ($20.95; blackmores.com.au). These tablets contain various ingredients to aid digestion, including fennel, ginger and peppermint, all of which relieve flatulence.

30: Percentage of Australians who have reported being constipated

Why it happens
A change in eating habits, an increase in physical or emotional stress, and poor sleep patterns can all throw off your gut's internal rhythms and reduce the muscle contractions that tell your colon it's "time to go".

The result: you may go days without a bowel movement even though you feel the need.

What to do

First, try a psyllium supplement, such as Metamucil. A review by the University of Illinois in the US determined that this type of fibre was effective in treating the initial onset of a blocked bowel. The downside is that research shows this strategy is hit or miss for chronic constipation.

Your next option: an over-the-counter laxative such as Durolax helps soften your stool with water, provoking the muscles in your colon to move things along, according to Dr Sandra Hoogerwerf, a gastroenterologist at the University of Michigan in the US. Then use these strategies:

Eat breakfast. After waking, colon activity increases threefold, and eating a meal doubles that rate, according to a study in the American Journal of Physiology. In fact, eat right after waking and you'll create a two-hour window in which your chances for a bowel movement are optimised.

Stay hydrated. Drinking water won't necessarily relieve constipation, but avoiding dehydration may help prevent it in the first place, say researchers at the University of Texas Medical School in the US.

Hit the weights. A study published in Medicine and Science in Sports and Exercise reports that resistance training accelerates the movement of food through your large intestine by as much as 56 per cent. In addition, other studies suggest that sedentary people are 50 per cent more likely to experience constipation than those who exercise regularly.

Four billion: cases of diarrhoea every year, worldwide

Why it happens
Your gastrointestinal tract is lined with cells that absorb liquid from food and drinks. Attacks from bacteria, viruses and parasites sometimes inhibit these cells from doing their job. The result: loose, watery stools.

What to do

Pop an Imodium Advanced It contains both loperamide and simethicone. Scientists at the University of Chicago found this combination relieved the symptoms of diarrhoea - runny stools and abdominal discomfort - faster and more effectively than products that contained just one of the two ingredients.

Eat yoghurt. It contains probiotics, which are beneficial bacteria similar to those that naturally reside in your gut and that keep levels of troublemaking bugs in check. Supermarket shelves are groaning with various products fortified with probiotics, but similar types of healthy bacteria can be found in any fermented milk product.