Constipation: nutritional help

Constipation is a condition in which bowel motions (faeces or stools) are hard and difficult to pass. When it comes to how often you move your bowels, there is no real definition of 'normal'. True constipation is related more to the consistency of the faeces than the frequency.

It is not normal to strain to pass a bowel movement, and it should not involve pain.

What causes constipation?

Constipation is actually a symptom and may be an indication of a number of problems. Some of the possible causes of constipation include:

  • changes in diet;
  • changes in daily routine (for example, going on holidays);
  • certain medicines such as pain medications, especially those that contain codeine, or some antacids;
  • nervous tension;
  • lack of exercise;
  • dehydration;
  • diseases of the bowel;
  • overuse of laxatives; or
  • older age.

What can you do for constipation?

Sometimes a change of lifestyle is enough, paying special attention to a few dietary factors to ease the problem of constipation and prevent it happening.

Eat more foods containing high levels of dietary fibre

The most common reason for hard or slow bowel motions is a lack of dietary fibre in your diet. Average consumption of dietary fibre in Australia is lower than recommended levels, and simple changes to replace low fibre foods with those with higher levels of dietary fibre is the first (and often the only) change required. Adding extra fibre to your diet should make your stools more bulky and easier to pass, but it may take a few days for you to notice an effect.

Most types of dietary fibre are broken down by 'good' bacteria in the large bowel (the colon). This helps with the health of the colon, although gases are produced as a by-product. Some people are concerned about this, but although it may be a social problem, it is not a medical one. If you increase your intake of dietary fibre gradually, it will help possible embarassment of increased production of gas.

The Australian National Health and Medical Research Council has set an adequate intake of dietary fibre as:

  • adult men: 30 grams a day;
  • adult women: 25 grams a day.

These are average values and some people may find higher levels of dietary fibre are necessary for them to avoid constipation.

A diet high in dietary fibre may also reduce your risk of obesity, cardiovascular disease, type 2 diabetes and certain cancers.

Dietary fibre occurs only in plant foods and does not necessarily appear fibrous. On the other hand, meat contains no dietary fibre, even though it may appear fibrous. The following are good sources of dietary fibre to include in your diet.

  • Wholegrains. Wholegrain cereals (such as oats, wholewheat breakfast cereals, brown rice, quinoa, cracked wheat), wholegrain breads and pasta are good sources of dietary fibre.
  • Fruits and vegetables, both raw and cooked, add extra fibre to your diet. All fruits and vegetables contain dietary fibre with top sources including green peas, spinach, broccoli, passionfruit, bananas, raspberries, pears, citrus fruit and apples.
  • Resistant starch. This is a form of carbohydrate that is not digested in the small intestine but is broken down by 'good' bacteria in the bowel, acting in a similar way to some types of dietary fibre. Resistant starch is found in pasta cooked to the 'al dente' stage, some especially bred types of corn, potatoes that have bee cooked and cooled and unripe bananas.
  • Unprocessed wheat, oat or rice bran can be added to some meals to increase the fibre content.
  • Legumes or pulses (such as dried beans, lentils, chick peas) are very good sources of soluble and insoluble fibre, and can be added to soups, salads and stews or made into burgers.
  • Nuts and seeds are high in fibre and can be added to salads, vegetable dishes and breakfast cereals, or eaten as a snack.
  • Psyllium husks provide soluble fibre and can be added to breakfast cereals, yoghurt and smoothies. Like other foods that contain soluble fibre (oats, some seeds and legumes), they can also help lower cholesterol. Psyllium husks are a component of a few commercial breakfast cereals and are also the main ingredient in some laxatives such as Metamucil. Drink extra water if you eat psyllium.

Fibre supplements

Fibre supplements are also available, but don't have all the nutritional advantages found in the foods that are high in dietary fibre.

If you are having ongoing problems with constipation, check with your doctor as it may be an indication of a more serious problem.

Drink plenty of fluids

Dehydration can exacerbate constipation. For good health, it's important to have plenty of fluids. Each day about 10 litres of fluid enters the digestive tract. This includes about 2 litres from the diet as well as digestive juices. About 8.5 litres of fluid is absorbed as food passes through the small intestine. Another 1.3-1.4 litres is absorbed in the large intestine and the rest becomes part of the stool. Dietary fibre and this liquid keeps the stools soft and easy to pass.

Aim to drink 8 to 10 glasses of liquids per day. This should be mostly water, but can also include tea (4 cups is fine), coffee (2-3 cups is fine), soup or other fluids. However, it is better to eat fruit than to drink juice as fruit also provides dietary fibre.


Regular exercise is also important for general health and will help keep your system healthy.

General hints

Try not to ignore your body’s needs when you feel the urge to have a bowel movement — take the time.

Remember, check with your doctor if:

  • you have an ongoing problem with constipation;
  • you notice blood in your bowel motion;
  • you have severe pain or fever;
  • constipation is associated with weight loss or feeling generally unwell.


1. Australian Government, NHMRC. Nutrient Reference Values for Australia and New Zealand, including Recommended Dietary Intakes. 2005. (accessed Oc t 2015).
2. Nutrition Australia. Fibre. (accessed Oct 2015).
3. NHS Choices. Constipation – prevention. (accessed Oct 2015).