What is IBS and SIBO? Review


This is a thorough review about what is IBS and SIBO? IBS is Irritable Bowel Syndrome and SIBO is Small Intestinal Bacterial Overgrowth. There is a world-wide prevalence that goes from 4 % to 30% of the people suffering from IBS and it is very uncomfortable making people stay at home because of the symptoms.

Keep reading to know the meaning, signs, symptoms and the difference of this two conditions. Find out if you are suffering from this disorder and how you can get better.

What is IBS and SIBO?

what is ibs and sibo

IBS and SIBO SOS Summit

What is IBS?

Irritable Bowel Syndrome is a functional gastrointestinal disorder that is characterized by recurrent patterns of abdominal pain associated with abnormal bowel motility which could be constipation or diarrhea or a combination of both, in the absence of an organic pathology. The cause of this disorder still is unknown that is why doctors make the diagnosis of IBS based on the symptoms that the patient might have.

What are the signs and symptoms of IBS?

  • Abdominal pain: diffuse mainly in the lower abdominal area although sometimes some people might feel pain in the chest or upper abdominal quadrant because of the gases.
    • It´s usually a cronic disfuse pain but might have occasional acute worsening.
    • The pain usually worsens after meals, and It might improve after defecation.
  • Abdominal bloating or distension
  • Altered bowel habits
    • Diarrhea
    • Constipation
    • Alternation between constipation and diarrhea
    • Postprandial urgency

IBS and SIBO SOS Summit

How to make the diagnosis of IBS?

To know if a person has IBS there are some clinical criteria based on the Rome IV guidelines. Based on these guidelines a person has IBS if the patient has had recurrent abdominal pain at least 1 day per week for 3 consecutive months and it is associated with 2 or more of the following symptoms:

  • The abdominal pain may be increased or unchanged by defecation.
  • There is a change in stool frequency.
  • There is a change in stool appearance.

What is the cause of IBS?

Doctors still haven´t found the root of the problem but we can understand what is the functional disturbance that explains the symptoms.

  • The abdominal pain is caused by visceral hypersensitivity.
    • After the meals the intestine wall abnormally quickly stretches because of an abnormal strong response of the sensory nerve endings in the intestine wall.
  • The abnormal bowel motility causes diarrhea, excess gas and bloating.
    • When the person eats short-chain carbohydrates like lactose and fructose, they are not well absorbed and stay in the intestine acting as solutes drawing water inside the lumen of the intestine.
    • The excess water causes the smooth intestine muscles to spasm which creates diarrhea. It also causes visceral hypersensitivity which produces abdominal pain.
    • Also, the gastrointestinal bacterial flora metabolizes the unabsorbed lactose and fructose and it produces gases which leads to bloating, abdominal distention, spasm and pain.

What are the risk factors for IBS?

There are many risk factors that can precipitate or trigger the development of Inrritable Bowel Syndrome (IBS) such as:

  • Diet rich in short-chain carbohydrates like:
    • Grains (lentils, beans, garbanzo)
    • Some cereals (wheat, bread, pasta, cookies)
    • Some fruits (apples, watermelons and mangoes)
    • Some vegetables (cauliflower, broccoli, sweet corn, raw vegetables, mushrooms)
    • Some dairy products (soft cheese, whole milk)
    • Some sweeteners (corn syrup, sucralose, fructose)
  • Gastroenteritis which are gastrointestinal infections by:
    • Viruses like Rotavirus, Norovirus and Adenovirus (stomach flu).
    • Bacterial food poisoning (travelers diarrhea) for example, caused by Salmonella or Campylobacter jejuni.
    • Parasites infections.
    • Yeasts infections.
  • Stress, anxiety and depression.

What is IBS and SIBO?

What is the IBS Treatment?

The treatment for Irritable Bowel Syndrome (IBS) is targeted to alleviate the symptoms that each person has and it´s different for every patient depending on how he/she is affected. In general the treatment is as follows:

  • Avoid foods with short-chain carbohydrates such as broccoli, beans and apples.
  • Constipation can be treated with a high fiber diet, drinking more water, laxatives and stool softeners.
  • Spams and abdominal pain is usually treated with antidiarrheals and antimuscarinics.
  • Specific treatment for stress, anxiety and depression if that´s the case.

What is SIBO?

Small Intestinal Bacterial Overgrowth is the accumulation of bacterial in the small intestine that normally lives in the large intestine. The large intestine is normally highly colonized by good bacterial, but the small intestine isn´t as much so, when the bacterial from the colon migrates and colonizes the small intestine it produces small intestine bacterial overgrowth.

What are SIBO symptoms?

SIBO symptoms are just the same as Irritable Bowel Syndrome IBS:

  • Abdominal pain, spams, bloating and distension
  • Constipation
  • Diarrhea
  • Constipation alternating with diarrhea

IBS and SIBO SOS Summit

Is there an association between SIBO and IBS?

Some studies have shown that there might be an association between Small Intestinal Bacterial Overgrowth SIBO and IBS Irritable Bowel Syndrome.

A study showed that SIBO might be present from 4% to 78% of IBS patients. Therefore, after a gastrointestinal infection like food poisoning or traveler´s diarrhea, part of the intestine might be damaged and it allows small intestine bacterial overgrowth SIBO and some people might present Irritable Bowel Syndrome IBS symptoms.

What are the risk factors for SIBO?

  • Previous gastrointestinal surgery
  • Gastrointestinal infections
  • Slow motility due to some diseases like diabetes or hypothyroidism
  • Colon Diverticulitis
  • Some drugs like opiates
  • Chron´s disease
  • Celiac disease
  • Fybromialgia

What is the cause of SIBO?

When a person suffers from a gastroenteritis, the bacteria like Salmonella or Campilobacter for example, produce toxic substances called toxins which damage the intestinal wall and produce inflammation and an immune activation, which produces slow motility of the intestine and bacterial overgrowth in the small intestine.

The small intestinal bacterial overgrowth leads to unabsorbed and fermented carbohydrates producing excess gas leaving the patient feeling bloating, abdominal pain, spams and diarrhea. Excess of hydrogen gas causes diarrhea whereas, excess of methane gas causes constipation.

How to make the diagnosis of SIBO?

First, your doctor will listen to your story and examine you. Then there is a test called the breath test that can show the presence of gas producing bacteria in the intestine. The lactulose breath test is better than the glucose breath test because the later is less sensitive which may leave some under diagnosed SIBO cases.

The hydrogen and methane breath test is based on the principle that when a patient with SIBO is given a load of carbohydrates (lactulose or glucose), they will be fermented by excess bacterial overgrowth in the small intestine, thus producing hydrogen gas or methane gas which can be measured in exhalation during a period.

The stool test is not useful in the SIBO diagnosis because it shows the presence of bacteria in the large intestine not the small intestine, that is why the breath test is used to assess the small intestine.

What is SIBO treatment?

The treatment of Small Intestinal Bacteria Overgrowth is mainly with antibiotics. For hydrogen gas producing flora it is better to use Rifaximin which is a non absorbable broad spectrum antibiotic that acts locally at the intestine attacking the excess bacterial overgrowth. A study shows that for methane gas producing flora, it is more effective to use a combination of Neomycin and Rifaximine.

Some studies recommend the use of probiotics which are very helpful in alleviating the symptoms related to gas, bloating and abdominal distension. Therefore, the use of Lactobacillus as and Rifaximin as well may reduce the abdominal pain and diarrhea.

Once you get the bacteria down, you´ll feel better and you´ll be able to tolerate more foods. Therefore, it is very important to follow a diet low in short-chain carbohydrates like the low FODMAP diet (low Fermentable Oligo – Di – and Monosaccharides and Polyols).

The low FODMAP diet limmits (not completely eliminates) foods that contain lactose (whole milk and soft cheese), fructose (corn syrope, some fruits and honey), fructans (wheat, onions and garlic), galactans (lentils), and polyols (sugar alcohols present in some fruits, vegetables and artificial sweeteners like sucralose). Over time, as you get better, you´ll be able to slowly introduce one food at a time as you watch how it makes you feel.

Good low FODMAP carbohydrates are found in some fruits (bananas, oranges, mandarins), some vegetables (carrots, sweet potatoes, tomatoes), cereals (oats, rice, gluten free bread), dairy products (lactose free milk, hard cheese), olive oil. A gluten free diet also helps, but it is recommendable to do a test for celiac disease before eliminating gluten from the diet to know if that is the cause of your symptoms.

Another recommendation is not to eat anything at least for 2 hours before going to bed at night so that, you can have a 12 hour period of fasting every night, which helps the cleansing motility, in other words, to clean the bacterial from the small intestine. At bedtime, it is recommendable to use the pro kinetics to assist this process of cleansing.

My final opinion

In my opinion, there are many cases of Irritable Bowel Syndrome (IBS) that are triggered by Small Intestinal Bacterial Overgrowth (SIBO) and if it is not correctly diagnosed the symptoms will be recurrent and chronic.

For those patients having SIBO as the cause of their IBS, the antibiotic treatment will cure the disease, although there might be some cases of recurrences. Therefore, it is very important to learn about the correct diet that will help you maintain the symptoms under control.

For more information about IBS and SIBO, attend the upcoming Online Summit. It´s free to register and you can also get some bonuses free gifts when you join. For instance, when you register, you´ll get free downloadable guides for recipes, diagnosis and treatment.

If you would like to know more about the IBS and SIBO summit read my review about this event, just click here: IBS and SIBO news.

If you have any comments, please don´t hesitate to leave them in the section below, and I´ll do my best to help you out.

Your friend,

Dr. Verónica Giannoni

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