Welcome to part 2 in our series on small intestine bacterial overgrowth (SIBO). If you have any ongoing gut disturbances—bloating, pain, excess gas, constipation or diarrhoea, then this article will be of interest to you.
The causes of SIBO are varied. They can be related to conditions and diseases that alter the function of the intestinal muscles, or partially block the intestine. SIBO can also be caused by bacterial gastroenteritis. A healthy gut requires good motility and the correct balance of bacteria.
Functional causes of SIBO
By functional, I mean the health of the gut muscles and lining. The gastrointestinal tract is one long muscular tube. The contractions of the tube help move the food along to its next processing station—stage of digestion and/or absorption.
The muscular contractions are also important to reduce the number of bacteria in the small intestine. So, anything that interferes with normal gut motility has the potential to cause SIBO. A lack of muscular activity would mean that bacteria could easily invade the small intestine from the colon.
#1 Neurological and muscular diseases
Any condition or disease that alters the muscular contractions of the gut can lead to SIBO. For example, diabetes and sleroderma (an autoimmune disease that can change the functioning of skin, blood vessels or organs of the body).
#2 Obstruction of the small intestine
Partial or intermittent obstruction of the small intestine can cause SIBO. Obstructions interfere with the transport of food and bacteria through the small intestine. Adhesions (scaring from surgery) can also lead to full or partial blockages.
Diverticuli are pouches that form in the small intestine. Bacteria can live in and multiply in these pouches ,if they are not moved on by the gut wall contractions.
Does irritable bowel syndrome cause SIBO?
Irritable bowel syndrome (IBS) is a long-term condition that has similar symptoms to SIBO:
- Abdominal bloating and distension
- Abdominal pain
- Excess gas
While IBS is not life threatening it interferes with the day-to-day enjoyment of life.
Research indicates that 50% of people with IBS also have SIBO.
Research indicates that 50% of people with IBS also have SIBO. At this point in time, there has been insufficient research focussed on the connection between these two gut conditions. Researchers are divided on opinion:
- IBS causes SIBO
- SIBO causes IBS
Other causes of SIBO
A bacterial gastroenteritis can also lead onto this condition, as the foreign bacteria can change the balance in the types of bacteria in the gut. An ongoing imbalance can lead to changes in gut motility too.
It is important following a bout of gastroenteritis that we choose foods that help re-establish a community of healthy bacteria.
Knowing the causes of SIBO are important, as the underlying cause as well as the SIBO need to be treated. But, the first step is to make sure that the diagnosis of our gut condition is correct. The diagnosis of SIBO is outline in part 3 of our series, coming soon.