Irritable Bowel Syndrome, also known as IBS, is one of the most common and debilitating gastrointestinal disorders that significantly affects the digestive system.
It is a group of symptoms which consistently occur together. The most common symptoms are stomach cramps, bloating, discomfort, diarrhoea and constipation which usually alternates with each other.
IBS can affect your everyday life.
Symptoms of IBS vary among people. As a functional Gastrointestinal (GI) disorder it comes in multiple forms.
IBS-C refers to IBS with constipation predominantly and it is one of the more common types.
IBS-D is also called IBS with diarrhoea.
IBS-M includes the mixed bowel habits i.e., alternating diarrhoea and constipation.
Post-Infectious IBS occurs after you have had a gut infection. Diarrhoea, vomiting are important signs.
Post-diverticulitis IBS. People are at risk of developing IBS after they have had diverticulitis.
The exact cause of IBS is unknown, but some factors appear to play a role in IBS:
- Altered muscle contractions in the intestine: if the muscle contracts stronger and for a longer period, then it may cause diarrhoea. If the muscle contractions are weaker, it can cause constipation.
- Sensitive nerves in the gastrointestinal tract; this can occur in response to gas or stool in the intestine causing the nerves to overreact. This may lead to discomfort and IBS symptoms.
- As mentioned above, post-infections IBS (PI -IBS) can occur after a bout of gastroenteritis (or sometimes referred to as a tummy bug). Food poisoning is a common cause of a bacterial infection in the gut. Not everyone who experiences food poisoning or gastric infection will go on to PI-IBS but it increase the risk. Symptoms can still develop many years after the infection which can make it difficult to identify.
- An imbalance of bacteria in the intestine called SIBO (Small intestinal bacterial overgrowth) results in an overgrowth of bacteria in the small intestine. Some studies have indicated that up to 80% of people with IBS have SIBO. Because of the prevalence of SIBO and the fact there is treatment available for it, we will discuss this in more detail below.
To understand the relationship between SIBO and IBS, we first need to look at what SIBO means.
SIBO stands for Small Intestinal Bacterial Overgrowth. It refers to the condition where there is an abnormal increase in the bacterial population of the small intestine.
Most of our gut bacteria reside in the large intestine and performs a variety of important roles in the body. A much lower number of bacteria are located in the small intestine. If there is an abnormally high number of bacteria in the small intestine, it can interfere with digestion and absorption.
Briefly explaining, if the movement of food particles in the digestive tract slows down, it provides optimal conditions for bacteria to overgrow, resulting in a range of symptoms, for example, diarrhoea, abdominal bloating, and may even lead to malnutrition. So, those with SIBO suffer almost the same symptoms as the people with IBS do.
This overlap of symptoms makes it confusing to reach a diagnosis. However, it is worth mentioning that the diagnosis and the management of SIBO can be quite straightforward, whereas IBS can only be diagnosed when all other possible diagnoses have been ruled out, meaning that IBS is a diagnosis of exclusion.
Undoubtedly, there are many other potential reasons for the development of irritable bowel syndrome, but further ongoing studies indicate that up to 80% of the people clinically diagnosed as IBS have SIBO too.