
Introduction:
What is it?
Small intestinal bacterial overgrowth (SIBO) occurs when there is an abnormal increase in the overall bacterial population in the small intestine — particularly types of bacteria not commonly found in that part of the digestive tract. This condition is sometimes called blind loop syndrome.

Symptoms
Common symptoms of SIBO, including gas and bloating, abdominal pain and distension are uncomfortable enough. But left unmanaged, SIBO can cause more serious complications with long-term consequences. Malabsorption of fats, proteins and carbohydrates can lead to malnutrition and vitamin deficiencies.
SIBO has been shown to cause constipation and may cause a slower transit time, which means that food stays in the digestive tract longer than it should. This slower transit time can lead to various symptoms such as nausea, abdominal pain and weight gain.
Bloating – a feeling of fullness and discomfort, especially 1-2 hours after eating meals rich in carbohydrates (sugars are a type of carbohydrate).
Abdominal pain – linked to the bloating, as the gases build up in the small intestine, they stretch the intestinal walls, and this can be very painful. In some people this pain can be crippling, really affecting their ability to perform ordinary daily tasks.
Excessive belching – once the gas has built up in the small intestine it has to go somewhere! Whilst its normal to belch after eating or drinking, especially after drinking something fizzy, SIBO can cause really excessive belching that is uncomfortable and embarrassing.
Reflux – one of the causes of SIBO is thought to be the prolonged use of proton pump inhibitors for reflux symptoms. These medications make the stomach less acidic and let bacteria through to the small intestine. When patients suffer from excessive belching, they can belch acid from the stomach into the gullet, causing symptoms that mimic reflux-like heartburn.
Flatulence/wind – again some wind is normal, after all everybody farts! Patients with SIBO are often very windy and the wind can be very smelly. For a SIBO patient this can mean not going out and may cause some relationship difficulties!
Diarrhoea/constipation – often seen as a symptom of irritable bowel syndrome (IBS), alternating diarrhoea and constipation can also be a symptom of SIBO. The mechanism for this symptom is less clear than the others but many doctors think that at least some people who think they have IBS actually have SIBO.
SIBO issues to be aware of:
- Vitamin A deficiency can cause vision problems and immune deficiency.
- Vitamin D deficiency causes osteoporosis and depression.
- Vitamin E deficiency interferes with healing.
- Vitamin K deficiency can cause easy bruising and bleeding.
- Lentils and beans.
- Wheat and rye.
- Natural and artificial sweeteners, including agave syrup, xylitol, sorbitol, and high fructose corn syrup.
- Dairy products like cottage cheese or ice cream.
- Certain vegetables, including onions, garlic, artichokes, cabbage, and cauliflower.
- The pH changes make it easier for bacteria from other areas to grow in the small intestine and allow different types of bacteria to thrive.
- Decreased intestinal motility, such as occurs with blind loop syndrome, keeps bacteria in the small intestine for a longer period of time than usual. This disrupts the normal balance of digestive enzymes.
A variety of illnesses may predispose you to SIBO. These medical conditions are generally diagnosed years before SIBO and may alter the environment of the small intestine, setting the stage for the condition to develop.
Conditions and circumstances associated with SIBO include:
- Celiac disease
- Chronic pancreatitis
- Cirrhosis of the liver
- Crohn’s disease
- Diabetes
- Scleroderma
- Bowel obstruction
- Intestinal surgery