What is SIBO
and what is IBS

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What is SIBO and what is IBS

Medically reviewed by:
Dr James Freeman

What is SIBO?

SIBO stands for small intestine bacterial overgrowth and is thought to be one of the leading underlying cause of general IBS.

Surprisingly, a quarter of the population suffers from IBS. Estimate range on how much of this is attributed to SIBO but some estimates suggest it maybe as high as 70-80%. It can cause excessive bloating, pain, gas, leaky gut, diahrrea or constipation.

A less talked about side effect is how it can destroy your enjoyment of food and life in areas outside the physical. It is treatable but hugely underdiagnosed.

SIBO can cause a plethora of other health problems. These include anxiety, brain fog, depression, hair loss, joint pain, weight gain/loss, and many other autoimmune conditions.

SIBO can cause secondary food intolerances, and we will help you understand why. This can make food unenjoyable and cause you to avoid things you love or are beneficial in a healthy and whole diet.

SIBO can be very painful and debilitating, but the good news is that it is treatable,[1] and you have options.

There are different types of SIBO, as explained below. Read on!

What is IBS?

IBS is a generic umbrella term used to describe irritable bowel syndrome. That is, any kind of gastrointestinal upset.


IBS-D stands for irritable bowel syndrome with diarrhea. IBS-C stands for irritable bowel syndrome with constipation. IBS-M stands for irritable bowel syndrome mixed with constipation and diarrhea.

IBS, IBS-d, IBS-c, or IBS-m are not really a complete diagnosis in themselves. Unfortunately, many medical practitioners do not recognise the difference in diagnosis of these bowel syndromes and instead treat them as one and the same.

1 Sorathia and Rivas, 2020

“Your doctor will tell you that you’ve got an irritable bowel, but that is exactly what you told them, so it doesn’t help you at all. When you can put a word to a condition, you stop thinking about it and its cause, and that’s exactly what has happened with IBS in medicine. SIBO goes a long way to explaining the problem which has been completely ignored by the medical profession and does, in fact, have a logical diagnosis and treatment is available.”
– Senior Physician

SIBO symptoms

    • Abdominal pain
    • Brain fog
    • Bloating
    • Nausea
    • Leaky gut
    • Weight gain
    • Weight loss
    • Diarrhea or constipation (sometimes both)
    • Reflux from the pressure on the stomach bag
    • Fatigue
    • Anxiety, irritability, restlessness, mood swings, or depression
    • Skin issues such as acne, psoriasis, or rashes
    • Nutrient deficiencies
    • Hair loss
    • Increased or bad-smelling flatulence
    • Joint pain
    • Food intolerances
    • Histamine intolerance

What is SIFO?

Small intestinal fungal overgrowth (SIFO) is characterized by an excessive number of fungal organisms in the small intestine associated with gastrointestinal (GI) symptoms.

Candidiasis is known to cause GI symptoms, particularly in immunocompromised patients or those receiving steroids or antibiotics.

However, of late, there is emerging literature that an overgrowth of fungus in the small intestine of non-immunocompromised subjects may cause unexplained GI symptoms. Two recent studies showed that 26 % (24/94) and 25.3 % (38/150) of a series of patients with unexplained GI symptoms had SIFO.

The most common symptoms observed in these patients were belching, bloating, indigestion, nausea, diarrhea, and gas.