Irritable Bowel Syndrome (IBS)
What is Irritable Bowel Syndrome (IBS)?Irritable bowel syndrome is a common digestive problem characterised most often by bloating, abdominal pain, flatulence, constipation and/or diarrhoea. It is defined as a benign, chronic disease and is sometimes considered to be a functional type of bowel disorder that is caused by heavy, muscular spasms in the colon (large intestine). IBS can cause people to miss work and social events, and there is often some associated anxiety and/or depression. Sometimes people find that their symptoms subside for a few months and then return, while others report a constant worsening of symptoms over time. The majority of sufferers are women and most have their first symptoms between the ages of 15 and 40.
What causes IBS?When the word 'syndrome' is used in medicine it indicates an umbrella term for a range of symptoms with no single, clear cause. This article sets out to review a range of current theories on the development of IBS.
People who suffer from IBS may have a colon (large intestine) that is particularly sensitive and reactive to certain foods and stress. The immune and nervous systems play a central role in the development of this condition and there are many neurological (nerve) and hormonal connections between the brain and the gut (as many as 2000 directly connecting nerve fibres). In fact, the intestines have the highest concentration of nerve cells in the body besides the brain (known as The Enteric Nervous System) and there is constant communication between the brain and the gut, particularly through nerve cells using the mood regulating neurotransmitter serotonin. This Enteric Nervous System (ENS) in the gut also contains approx. 75% of the body’s total immune cells and is clearly a highly complex information processing centre.
We are effectively considering two 'brains' in continual conversation and therefore they communicate dysfunction in each other very quickly. It is not surprising that a great amount of research suggests that psychological and emotional factors can trigger neural and hormonal changes that in turn cause dysfunction in the digestive tract. However, IBS is a complex matter and there are multiple issues to consider.
IBS may often be linked to small intestinal bacterial overgrowth (SIBO), a condition where abnormally large numbers of bacteria are present in the small intestine. These types of bacteria can have a similarity to those more commonly found in the colon and are considered to establish an imbalance in the gut. It is also thought that many carbohydrates (sugars) cannot be successfully broken down and absorbed within the small intestine. As a result, these sugars are rapidly fermented by bacteria in the bowel which draws in fluid and produces gas, pain and bloating. Therefore, a lack of the appropriate pancreatic and intestinal enzymes could be an issue for IBS sufferers.
The transit time of fluids through the gut is determined by peristalsis (muscular movement), bowel wall integrity and other factors. Any condition that reduces muscular activity in the small intestine will slow transit time, allowing bacteria to remain longer and multiply. Reduced muscular activity may also allow bacteria to spread backwards from the colon and into the small intestine causing a bacterial imbalance.
Alternatively, malabsorption of sugars and carbohydrates in the small intestine caused by rapid transit time can also be problematic, allowing increased amounts of sugar and carbohydrate to reach the colon where greater amounts of gas are produced.
Some research states that IBS may be caused by bacterial, viral, fungal or parasitic infection in the gastrointestinal tract. Commonly cited viral infections include Epstein Barr Virus (EBV), HHV6 (Human Herpes Virus) and Cytomegalovirus (CMV) - all of which may also have a link to Chronic Fatigue Syndrome (see page on CFS for details). Studies show that people who have had gastroenteritis or food poisoning sometimes develop IBS, otherwise called post-infectious IBS. Bacteria such as brucella, staphylococcus and campylobacter are commonly diagnosed with appropriate blood tests. Some people may carry miasms (inherited toxins) that have ben passed through several generations, common examples being luesinum (from syphilis) and bacilinum (from tuberculosis). IBS may also be associated with a mild or severe histamine intolerance, sometimes referred to as Enteral Histaminosis (see page on inflammation for details).
Researchers have also found very mild coeliac disease in some people with symptoms similar to IBS. People with coeliac disease cannot digest gluten, a substance found in wheat, rye, and barley. An immune response is triggered in response to the gluten causing significant pain.
Other research suggets that serotonin is linked with normal gastrointestinal (GI) functioning. Serotonin is a neurotransmitter, a "feel good "chemical that delivers messages from one nerve cell to another, and 95% of the serotonin in your body is located in the GI tract while the other 5 percent is found in the brain. It affects the nervous system and functions to regulate appetite, sleep, memory, learning, temperature, mood, behaviour, and critically muscular movement. Reduced levels of serotonin in the brain may be linked to depression as some depressed patients are seen to have lower concentrations of metabolites of serotonin in their brain tissue and cerebrospinal fluid. Cells that line the inside of the colon work as transporters and carry the serotonin out of the GI tract. People with IBS, however, have dysfunctional receptor activity that causes abnormal levels of serotonin to remain in the GI tract causing problems with bowel movement, intestinal fluid levels and pain.
Finally, some researchers have also found that women with IBS may have more symptoms during their menstrual periods, suggesting that reproductive hormones can worsen IBS problems.
We can see that IBS is a complex matter and the integrated approach is methodical in identifying the relevant issues for each individual.