Bite, chew, swallow. We can see that much of the digestion process. But what goes on beyond the throat is like guessing what that splutter from under your car's hood means. With no instruction manual to clue owners in on what is happening in our 26cm-long oesophagus, fist-sized stomach, 7m-long small intestine and 2m-long colon, we are often left puzzled by what emerges.

So, we have done the dirty work for you by asking the experts the questions about your inner workings.

>>Is making a deposit in the toilet once a week normal?

'Anything between three per week and three per day is considered normal,' says Dr Dede Selamat Sutedja, senior consultant at the National University Hospital's department of gastroenterology and hepatology. Even so, take that as a general guideline as many factors can affect the frequency of your bowel movements.

Dr Gwee Kok Ann, consultant gastroenterologist at Gleneagles Hospital, explains: 'In healthy people, these factors can include the amount of food we eat, intestinal transit time (how long it takes for food to end up as poop), as well as lifestyle factors such as stress, quality of sleep, and timing and regularity of meals.'

Infrequent bowel movements are not necessarily a bad sign unless it is a recent development, in which case it could be a sign of the start of a bowel disorder, says Dr Gwee.

If you do not go often enough, say every four days, you may develop faecal impaction. This happens when the rectum walls are stretched so thin by the build-up of stool that they lose their tone. Your body does not register the urge to purge until the high pressure causes abdominal cramps, bloating and even vomiting. By then, you will have to see a doctor.

In extreme cases, some may have a sensitive bowel that gives them frequent urges to run to the toilet. According to Dr Gwee, this may be caused by infection and diseases like ulcerative colitis or irritable bowel syndrome.

>>Why do I need to visit the toilet after a heavy lunch?

The post-meal rumble in your tummy is probably last night's dinner bidding goodbye. This is because it takes 24 to 48 hours for food to be processed.

The slower the intestinal transit time, the more constipated you will be, says Dr Gwee.

A couple of factors can affect transit time. Anxiety can speed things up in your gut, which is why it is not unusual to run to the toilet just before an exam or important presentation. Coffee and spicy and oily food also stimulate the gastrocolic reflex - a reflex system that tells the colon to empty when food hits the stomach.

It is your body's way of making sure that food from the stomach is moved to the bowels and cleared to make way for the new load.

>>Why do I get constipated?

Constipation occurs when the movement of stool in your colon is slow. More water from the faeces will get absorbed, resulting in harder, smaller stool, says Dr Sutedja. You get wet and loose types when the transit time is rapid, he says.

Even if you go daily or a few times a day, you are constipated if you are struggling to pass small pellets each time and experience an incomplete sense of evacuation, says Dr Gwee.

Fibre will smooth things out for mild constipation. But a severe case caused by a sluggish bowel is not helped much by increasing fibre intake, says Dr Gwee. In fact, too much fibre can lead to constipation.

Fibre supplements, stool softeners and over-the-counter and prescription laxatives can provide relief. But consider adding coffee and oily foods to the list too. 'The health-conscious can opt for fish oils and olive oils. My advice is to take them in the morning,' says Dr Gwee.

>>Why do I feel constipated after recovering from diarrhoea?

First of all, there is less stool to pass as everything was flushed out during the diarrhoea. And your body behaves like a sponge after the runs, absorbing fluid from the intestines and stool as much as it can to recover the fluid lost, thus resulting in constipation, explains Dr Teoh Tiong Ann, consultant colorectal and general surgeon from Mount Elizabeth Medical Centre.

His advice is to give your bowel system a few days to get back its groove. The best bet for post- diarrhoea constipation, says Dr Teoh, is to stay adequately hydrated.

'Sometimes, a change in diet can lead to a reduced intake of dietary fibre,' says Dr Gwee. If so, try to resume fibre intake once the diarrhoea is over. Start gradual and go with soft fruit and vegetables.

>>Why are women more constipated before or during their period?

Experts are not sure why women's bowels act up during menstruation. Dr Teoh says it could well be related to hormonal changes, fluid shifts and water retention during this period. 'Some women also have food cravings around the menstrual periods and these will impact on the stool,' he says.

Regardless of their diet, women as a group have a slower intestinal transit time than men due to hormonal influences, says Dr Gwee.

His advice is to consume more fibre and water during the time of the month to keep things running smoothly.

>>How do I avoid overdoing it in the toilet to avoid piles?

The consistency of the stool is often what makes one strain during a bowel movement, says Dr Teoh.

Regular bowel movements will give you an easier time in the toilet because the longer the stool remains in the rectum, the drier and harder it gets, says Dr Teoh.

Ironically, hard stool is sometimes formed by excessive fibre intake, especially in the absence of sufficient fluid intake, says Dr Gwee.

People who have chronic constipation, and who do not respond to simple measures like fibre and fluids should see their doctors for a stool softener, available as syrups, enemas or suppositories.

The article is from this month's issue of Shape. Find out more from Singapore's No. 1 active lifestyle guide for women, now at newsstands for $5.