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Irritable bowel syndrome, often referred to by the initials IBS, is a functional disorder of the colon or large intestines.  It is classified as a functional disorder because the colon shows no evidence of disease.  IBS is diagnosed after all other possible digestive disorders and diseases are ruled out (1).  Although IBS sufferers can experience immense pain, the condition is not believed to permanently damage the colon or sections of the digestive tract (1).

IBS is different from IBD (inflammatory bowel disease).  IBD refers to chronic conditions that cause inflammation in a part of the intestines.  People with IBD have inflammation, ulcers, and other damage visible inside the digestive tract (2).


Scientists are still unsure what causes the condition and do not have a definitive cure.  Researchers have concluded that IBS is not caused by stress or strong emotions; however, stress and strong emotion can aggravate the symptoms of IBS.

Research has shown that the nerves and muscles in the bowel tend to be extra sensitive in people with IBS.  This can cause excessive muscle contraction if too much food is consumed causing the bowel to overreact with cramping and severe pain when the bowel stretches.

Despite the lack of one clear cause, the following risk factors have been identified:

  • Food: eating or drinking certain foods or beverages including wheat, dairy products, citrus fruits, beans, cabbage, milk, and carbonated drinks.
  • Stress
  • Hormones: women have a higher chance of developing IBS than men, suggesting hormone changes play a role.  Also, IBS seems to be worse during or around menstrual periods (3).


Irritable bowel syndrome is a collection of symptoms relating to a disturbance of the large bowel, also known as the colon. These symptoms may include:

  • Abdominal pain or discomfort, often relieved by defecation
  • Chronic diarrhea or loose or watery stools
  • Constipation or a combination of constipation and diarrhea
  • Off-white mucus in stools
  • A bloated or swollen abdomen
  • A sensation of incomplete bowel movement
  • For women, an increase in symptoms during menstrual cycles
  • Excessive intestinal gas
  • Continuous unease around the abdomen
  • Urgency – a need to rush to the toilet (3,4)

For more information on IBS and diagnosis:  1. Talk to your doctor  2. Visit the International Foundation for Functional Gastrointestinal Disorders website  3. Visit the Mayo Clinic website 


IBS is one of the most common gastrointestinal conditions in the United States, affecting between 10-15% of Americans.  It is often misdiagnosed as colitis, nervous diarrhea, nervous colon, nervous bowel, or spastic colon.  A study by the International Foundation for Functional Gastrointestinal Disorders found that 78% of those diagnosed with IBS reported having continuous or frequent reoccurring abdominal pain in the six months leading up to the study. The study also reported that those suffering from IBS restricted their usual activities for about 20% of the calendar year due to their condition (5).


There is no known cure for IBS; however, there are several treatments available for the different symptoms of the condition. It is important that you seek advice from your doctor for the best treatment for you as some drugs can make the condition worse. Drugs that may help target certain symptoms include (4):

  • Antispasmodics: work by relaxing the muscles of the stomach and intestines.  Possible side-effects include heartburn, constipation, dry mouth, and difficulty passing urine (6).
  • Medications for diarrhea: such as Imodium, Lomotil or Questran.  Possible side-effects include dizziness, fatigue, abdominal pain, constipation, nausea, dry mouth, and angioedema (7).
  • Laxatives: work to relieve constipation.  Marketed as such as Fybogel, Regulan, Celevac, and Duphalac.  Possible side-effects include flatulence, cramps, diarrhea, feeling sick, and bloating (8).
  • Tricyclic antidepressants: block the absorption serotonin and norepinephrine.  Possible side-effects include dry mouth, constipation, sweating, slight hesitancy in passing urine and slight blurring of vision (9,10).
  • SSRI antidepressants: specifically targets the neurotransmitter serotonin.  Possible side-effects include nausea, headache, and rarely, changes in liver chemistry tests (10).


Practices to Help Support Gastrointestinal Health:

  • Use the low FODMAP diet
  • Identify and avoid food triggers
  • Eat high-fiber foods
  • Drink plenty of fluids
  • Exercise
  • Get sufficient sleep (3,4)

Natural Supplements That Support Gastrointestinal Health:


  1. Irritable Bowel Syndrome. International Foundation for Functional Gastrointestinal Disorders. Accessed July 11, 2018.
  2. IBS vs. IBD: What Are the Differences Between Symptoms? MedicineNet. Accessed July 11, 2018.
  3. Irritable bowel syndrome. Mayo Clinic. Accessed July 11, 2018.
  4. Symptoms & Causes of Irritable Bowel Syndrome. National Institute of Diabetic and Digestive and Kidney Diseases. Accessed July 11, 2018.
  5. IBS Patients: Their Illness Experience and Unmet Needs. International Foundation for Functional Gastrointestinal Disorders. Accessed July 11, 2018.
  6. Antispasmodic Medicines. Patient. Accessed July 11, 2018.
  7. Antidiarrheals. Medscape. Accessed July 11, 2018.
  8. Laxatives. Patient. Accessed July 11, 2018.
  9. Antidepressants. Patient. Accessed July 11, 2018.
  10. Antidepressants. IBS. Accessed July 11, 2018.
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  16. Spiller R. Review article: probiotics and prebiotics in irritable bowel syndrome.  Aliment Pharmacol Ther. 2008 Aug 15;28(4):385-96. doi:10.1111/j.1365-2036.2008.03750.x. 
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