Supplements for Constipation

Supplements for Constipation

By medical nutritionist Dr Sarah Brewer, an expert in food, herbs and supplements

Constipation is a common and distressing problem which affects between five to 20 percent of people, depending on how it is defined. Women are twice as likely to be affected as men, as the female hormone, progesterone, has a slowing effect on bowel movements.

If bowel symptoms persist, despite diet and lifestyle changes, always seek medical advice. Constipation can occur as a result of health conditions such as irritable bowel syndrome, depression, underactive thyroid, neurological conditions or as a side effect of medication. Often, however, there is no obvious cause. This is known as functional constipation and is where supplements can really help.

Magnesium is needed for muscle contraction and has a natural laxative effect by drawing fluid into the bowel. Lack of magnesium can be an underlying cause of constipation associated a low fibre, processed diet. Research shows that people with the lowest magnesium intakes are 30 percent more likely to experience constipation than those with the highest intakes.

Fibre supplements, such as psyllium, are often advised to help maintain bowel regularity. Fibre ‘feeds’ bowel bacteria and absorbs water to add bulk which gets things moving. This approach usually works but it can take up to four weeks to notice the benefit. Don’t increase your fibre intake too quickly or you may experience bloating and discomfort. Increase your fluid intake too, so the fibre doesn’t dry out and make your symptoms worse. Dietary sources of fibre include wholegrains, fruit, vegetables, beans, salads, nuts and seeds (eg. chia and flaxseed).

Prune juice is an excellent source of soluble fibre, but the reason why it is such an effective laxative is that it contains a laxative substance called hydroxyphenylisatin which stimulates secretion of fluid into the bowel and intestinal contractions. This natural laxative is found in whole prunes as well as prune juice.

Probiotics are also helpful for constipation by producing lactic acid and enzymes that help break down dietary components to aid digestion and promote bowel regularity. Having insufficient levels of probiotic bacteria increases the chance of developing constipation and is associated with irritable bowel syndrome and diverticular disease (outpouchings in the lining of the large bowel from straining with constipation). Studies show that probiotic yoghurt and supplements can improve stool consistency and symptoms of straining during pregnancy, and in people with irritable bowel syndrome. In people with function constipation (no obvious cause) results from 14 clinical trials show that probiotic supplements improved the rate at which contents passed through the bowel (transit time) by over 12 hours, improved stool consistency and increased stool frequency by 1.3 bowel movements per week.

Prebiotics are non-digestible forms of fibre, such as fructo-oligosaccharides (FOS) and galacto-oligosaccharides (GOS) that act as a food source for probiotic bacteria in the bowel. They can be used on their own, or combined with probiotic supplements to increase their effectiveness.

About Dr Sarah Brewer
Dr Sarah Brewer is a medical nutritionist and an expert in food, herbs and supplements. She qualified from Cambridge University with degrees in natural sciences, medicine and surgery. After working in general practice, she gained a master’s degree in nutritional medicine. Sarah is a licensed medical doctor, a registered nutritionist and a registered nutritional therapist.


Subscribe to her newsletter to get a FREE 46-page PDF Do You Need A MultiVitamin? at For more information on diet and supplements, visit Dr Sarah Brewer’s nutritional medicine website at

Comments are closed.