Digestive system

The human digestive system

The digestive (or gastrointestinal) system is a long, muscular tube that extends from the mouth to the anus.2
It is responsible for breaking down the food it receives from the mouth into nutrients, absorbing the nutrients and then removing the waste materials from the body.2

The colon or large intestine is an essential part of the digestive system as it has many important functions which include:3

  • the absorption and secretion of electrolytes and water3

  • storage and excretion of waste materials3

The contents of the gut are liquid when they reach the large intestine however, when waste is eliminated, it is solid (i.e. stools), as the colon is very effective in absorbing water from the contents of the gut.4
Bacteria are found in large numbers in the colon and help to further breakdown the gut contents and produce some vitamins, such as vitamin K.4 These bacteria are essential for healthy intestinal function.4 Infections, poor diet, stress, travel, food poisoning and medications can disrupt the healthy balance of bacteria in the gut which can lead to diarrhoea.4,5

Good bacteria vs Bad bacteria

Intestinal bacteria can be divided into two groups:3

  • Non-pathogenic or “good?bacteria

    These bacteria enhance the body’s immune system, stop the growth of bad bacteria, improve digestion, decrease gas production, increase the absorption of essential vitamins and produce certain vitamins.3

  • Pathogenic or “bad?bacteria

    These cause diarrhoea, infections, liver damage, and can be cancer-causing.3



Normal stools are solid because the colon is very effective in absorbing salts, nutrients and water from the contents of the gut.6
Diarrhoea is defined as “a change in bowel movements with an increase in the water content, volume and usually frequency of stools, mainly due to infectious causes? 7


Diarrhoea is classified by the length of time that the condition lasts:8

  • Acute: lasting from several hours to 2 weeks

  • Persistent: lasting longer than 2 weeks but less than 4 weeks

  • Chronic: lasting longer than 4 weeks


There are many different causes of diarrhoea.9
The most common cause in both adults and children is a gut infection (gastroenteritis).9

Gastroenteritis can be caused by:9

  • A virus (such as norovirus or rotavirus)

  • Bacteria (Clostridium difficile, Salmonella, Campylobacter, Shigella and Escherichia coli )

  • A parasite (such as parasites that occur in contaminated water which cause giardiasis)

Other causes of diarrhoea can include:9

  • Stress/anxiety

  • Alcohol

  • Food allergy

  • Medications such as antibiotics, laxatives, non-steroidal anti-inflammatories (NSAIDs) or chemotherapy drugs

  • Functional gut disorders such as Irritable Bowel Syndrome (IBS)


The main symptom is frequent watery stools but there can be other associated symptoms such as:9

  • Stomach cramps

  • Nausea and vomiting

  • Headache

  • Loss of appetite

If the diarrhoea is excessive, the body can lose large amounts of water which can lead to dehydration. 9
Dehydration needs to be treated quickly to prevent serious health issues.9 Dehydration in children presents as drowsiness and irritability, pale skin, cold hands and feet, infrequent urination.9 In adults it can be seen when there is tiredness or lack of energy, loss of appetite, nausea, dizziness, sunken eyes, muscle cramps, and a rapid heartbeat.9

It is essential to seek help quickly from a medical professional if you are concerned about dehydration in yourself or your child or any of the following occurs:9

  • Your baby or child has had six or more episodes of diarrhoea in the last 24 hours9

  • Your baby or child has vomited three or more times in the last 24 hours9

  • Your child has a severe or continuous stomach ache9

  • You or your child have bloody or very watery stools9

  • You or your child show signs of dehydration9

  • You are vomiting persistently9

  • Your stools are dark or black(may be a sign of bleeding inside your stomach)9

  • You have lost a significant amount of weight9

Treatment of Acute Diarrhoea

Some common treatments include8:

  • Oral Rehydration Solution

    The most important treatment of diarrhoa involves replacing lost fluids(rehydration)8. An oral rehydration solution(ORS) consists of water containing salts and glucose. This solution is absorbed in the small intestine to help replace lost fluids and electrolytes.8

  • Zinc

    The World Health Organization(WHO) recommends the use of zinc supplementaion as it has been found to decrease duration and severity of an episode of diarrhoea and reduces the likelihood of subsequent infections for 2 to 3 months.10

  • Probiotics

    Probiotics are live microorganisms which have health benefits through their influence on gut microflora.5

    These benefits include stimulating and enhancing the immune system, competing with harmful bacteria for adhesion space and nutrients and producing substances which are toxic for some of the harmful bacteria.5

For a probiotic to work, it needs to be alive(viable) and able to survive the journey through the gut.5 The probiotic has to be able to resist stomach acid, bile salts and pancreatic enzymes in order to reach its destination in the small intestine so that it can adhere to the gut wall and colonise there5. While there are many probiotics available in food and medications, it is important to choose one which has proven efficacy as different probiotics vary in this regard.5


What is Inteflora?1

Inteflora is a probiotic and is classified as an antidiarrhoeal medication

Inteflora contains the active ingredient Saccharomyces boulardii which is a living yeast.

How does it work?1

Inteflora contains Saccharomyces boulardii, a yeast which is active in the digestive system.

It acts in two ways to re-establish the normal intestinal ecosystem and reduce diarrhoea by:

  1. Stopping the overgrowth of pathogenic or “bad?bacteria (such as E.coli, Salmonella typhi, and Shingella dysenteriae) and fungi (such as Candida albicans) which can cause diarrhoea.

  2. Enhancing the body’s natural immune response to bacterial and fungal invasions.

Inteflora also makes and supplies vitamin B within the intestinal tract.

Who can use Inteflora?1

Inteflora is suitable for the whole family: infants, children, adults and the elderly.

When should Inteflora be used?1

  • Episodes of diarrhoea

  • Inflammation and infection of the small/or large intestines(colitics and/or enterocolitics)

  • Antibiotic use to prevent and treat intestinal problems like diarrhoea, candidiasis, colitis

  • Prevention of diarrhoea in patients who are being tube fed

How should Inteflora be taken?1

One capsule of Inteflora should be taken twice daily or as your doctor prescribes it.

Inteflora can be taken in conjunction with antibiotics as the yeast Saccharomyces boulardii is genetically resistant to antibacterial agents.

Inteflora can be taken in conjunction with other anti-diarrhoeal medication.

Benefits of Inteflora1

Can be taken by the whole family - from infants to elderly.

Can be taken with antibiotics ?unlike many other probiotics which are affected by antibiotics, Inteflora is a yeast which is genetically resistant to antibacterial agents so will work even when taken with antibiotics.

Studies have shown that:

  • S.  boulardii, the active ingredient in Inteflora, significantly reduces the frequency and the duration of acute diarrhoea by approximately 24 hours.7

  • S.  boulardii  accelerates recovery and reduces the risk of prolonged diarrhoea.11

  • S.  boulardii  has increased efficacy if given in the first 48 hours of an acute diarrhoeal illness.11

  • S.  boulardii  is a well-tolerated treatment.12

  • Studies have shown that the use of oral S.boulardii significantly reduced the risk of antibiotic associated diarrhoea.13, 14

  • Inteflora is trusted by healthcare professionals and patients worldwide.15

  • Inteflora (S.boulardii CNCM I - 745 ) is the number one probiotic worldwide.15**


  1. Package Insert

  2. Ruiz, AR. Overview of the digestive system. Merck Manual Consumer version. Accessed 01/09/2016. Available at: http://www.merckmanuals.com/home/digestive-disorders/biology-of-the-digestive-system/overview-of-the-digestive-system

  3. Gibson GR, Roberfroid MB. Dietary Modulation of the Human Colonic Microbiota: Introducing the concept of prebiotics. The Journal of Nutrition. 1995;125:1401-1412.

  4. Ruiz, AR. Large Intestine. Merck Manual Consumer version. Accessed 01/09/2016. Available at: http://www.merckmanuals.com/home/digestive-disorders/biology-of-the-digestive-system/large-intestine

  5. Miles L. Are probiotics beneficial for health? Nutrition Bulletin. 2007;32:2-5.

  6. Digestive Disorder Foundation. Information about acute diarrhoea. Accessed 01/09/2016. Available at: http://www.bsg.org.uk/patients/general/acute-diarrhoea.html

  7. Dinleyici EC, Eren M, Ozen M, et al. Effectiveness and safety of Saccharomyces boulardii for acute infectious diarrhoea. Expert Opin. Biol. Ther. 2012;12 (4):395-410.

  8. MacGill M. Diarrhea: causes, symptoms and treatments. Medical News Today. Accessed 01/09/2016. Available at: http://www.medicalnewstoday.com/articles/158634.php

  9. NHS Choices. Diarrhoea ?information prescription. Accessed 01/09/2016. Available at: http://www.nhs.uk/Conditions/Diarrhoea/Pages/Introduction.aspx

  10. World Health Organization. Zinc supplementation in the management of diarrhoea. Accessed 01/09/2016. Available at: http://www.who.int/elena/titles/bbc/zinc_diarrhoea/en/

  11. Villarruel G, Rubio DM, Lopez F, et al. Saccharomyces boulardii in acute childhood diarrhoea: a randomized, placebo-controlled study. Acta Paediatrica 2007;96(4):538-541.

  12. Billoo AG, Memon MA, Khaskheli SA, et al. Role of a probiotic (Saccharomyces boulardii) in management and prevention of diarrhoea. World J. Gastroenterol.2006;12(28):1447-4560.

  13. Szajewska H, Kolodziej M. Systematic review with meta-analysis: Saccharomyces boulardii in the prevention of antibiotic-associated diarrhoea. Aliment. Pharmacol.Ther. 2015;42(7):793-801.

  14. Shan LS, Hou P, Wang ZJ, et al. Prevention and treatment of diarrhoea with Saccharomyces boulardii in children with acute lower respiratory tract infections.Beneficial Microbes. 2013;4(4):329-334.

  15. IMS data 2016

*  In association with oral rehydration solution

**   No.1 in value