Abdominal Pain, Fatigue, Constipation, Diarrhea: Could your symptoms be from Small Intestinal Bacteria Overgrowth (SIBO)?

By Jessica Yoches, CNTP  October 1, 2014

The importance of healthy digestion is known to be a crucial component for overall health, as is the balance of microbes in the gut between good, gut friendly bacteria and “bad” or pathogenic bacteria.  Large amounts of gut friendly bacteria reside in the large intestine carrying out vital functions such as synthesizing vitamins; stimulating growth of the gut lining and immune system; and improving muscular activity. In a healthy digestive system however, minimal amounts of bacteria reside in the small intestine so problems arise when bacteria begins to colonize there. Small intestine bacteria overgrowth is difficult to diagnose because its symptoms are similar to many other gut issues like IBS, and it often gets overlooked. Let’s explore what SIBO is, the causes, common symptoms, and how to diagnose and treat it.

What is SIBO?

SIBO is defined as the “presence of abnormally high bacteria in the small intestine.” The surfaces of the cells lining the small intestinal tract are normally free from colonized clusters of bacteria, and are separated from the inner lining by a layer of mucus.  Bacteria entering the digestive tract from the mouth get attacked first by Hydrochloric Acid (HCL) in the stomach, and then again in the small intestine via enzymes and immunoglobulin secretions.  70% of the immune system resides in the Gut, meaning the integrity of the gut’s immune system is crucial in fighting off viruses, bacteria, and parasites entering the small intestine.

Intestinal motility is also important for preventing SIBO.  The muscularis layer of the gut wall contains nerves and muscle fibers that move food through the GI tract, sweeping it efficiently from the stomach to the ileocecal valve into the large intestine. If the ileocecal valve has problems closing then bacteria can reenter the small intestine; if gut motility is impaired then bacteria are not swept out efficiently, giving them time to grow in the small intestine. The bacteria compete for the body’s nutrients, digesting food while creating gas that causes bloating and stomach distension, and producing toxic substances that trigger diarrhea.

Small Intestine Bacteria Overgrowth is linked to many other systemic conditions including:

  • IBS (Irritable Bowel Syndrome)
  • Diverticulitis
  • Celiac’s
  • Crohn’s disease
  • Autoimmunity
  • Asthma
  • Fibromyalgia
  • Rosacea
  • Cystic fibrosis

IBS specifically is linked with SIBO with a high rate of symptoms that overlap; 80% of patients with IBS have SIBO.

What causes SIBO

The top offender causing Small Intestine Bacteria Overgrowth (SIBO) is the consumption and poor absorption of carbohydrates; a high correlation exists between SIBO and diets high in refined carbohydrates. Gut bacteria feed off these refined carbohydrates, fermenting them and creating toxic byproducts. The most difficult to digest are lactose, fructose, sugar alcohols, and resistant starch present in bananas, corn, certain rice’s, cereals and some gluten free products. These foods have high fermentation potential.

According to one source: The most common cause I see in my functional medicine clinic is from a diet high in sugar, alcohol, and refined carbohydrates.” Bacterial overgrowth involves not just one type of bacteria, but a variety.  Some bacteria eat bile salts that aid in lipid digestion, and without bile, fats cannot be digested properly leading to diarrhea. Another type of bacteria emits toxins that damage the intestinal lining and prevent nutrient absorption.

In healthy digestion, the muscular action of pushing food from the stomach to the colon sweeps bacteria through, leaving minimal amounts behind in the small intestine. When this action is impaired, food and bacteria stay in the intestines longer, giving bacteria more time to reproduce and to spread backwards from the large intestine. Two conditions that directly affect the muscle and nerves guiding food transit are diabetes and scleroderma. Diabetes damages the nerves that control muscle movement, while scleroderma damages the muscles directly. Other physical aspects in the gut causing SIBO are diverticulitis, small pouches forming in the intestinal wall that collect bacteria, and scars from either surgery or Crohn’s disease.

Other causes of SIBO include: poor HCL production and low stomach acidity, use of acid-blocking drugs, antibiotic use, immune deficiency, neurological disease, food poisoning, pancreatic enzyme deficiency, poor ileocecal valve function, and stress. Stress triggers an immune response that stimulates nerves of the GI system, triggering IBS symptoms. Use of proton pump inhibitors or PPI’s decreases gastric acid that is crucial in killing off bacteria and other pathogens in the stomach before they reach the small intestine.


The symptoms of SIBO are very similar to many other digestive issues, such as IBS. Symptoms like bloating can worsen as the day progresses, especially after consuming many carbohydrates. Some symptoms are chronic, while others fluctuate month to month. Common symptoms include:

  • Bloating
  • Gas
  • Constipation
  • Diarrhea
  • Abdominal pain
  • Heartburn
  • Autoimmune diseases
  • Fibromyalgia
  • Weight loss
  • Night Blindness
  • Anemia
  • Extreme fatigue, or chronic fatigue syndrome
  • Diabetes
  • Food intolerances (to lactose, gluten, fructose, casein etc)
  • Vitamin and mineral deficiencies – *See our Nutrition Therapy
  • Fat malabsorption and fatty stools
  • Leaky Gut

Diagnosis methods

Because symptoms are similar to many other conditions, SIBO is difficult to diagnose. However, a couple of options including stool samples, a hydrogen breath test, or an organic acid test. Stool tests are inaccurate because they cannot evaluate small intestinal bacteria; the breath test is complicated and doesn’t always catch SIBO. The organic acid test is more conclusive as it evaluates bacterial byproducts from a urine sample. Small intestinal bacteria create wastes that are excreted with urine.  Some diagnoses are as simple as looking at the symptoms and diet, and going ahead with treatment to see if the patient reacts positively. At the Healing Center, we diagnose SIBO via muscle testing and our Zyto Scan.

Treatment Options

Treatment options include antibiotics, probiotics, herbs, and nutritional therapy. While the antibiotics are effective at quickly wiping out the bad bacteria, the prevalence of recurrence is high, with relapse in 44% of patients 9 to 10 months after successful treatment.  Small Intestine Bacteria Overgrowth (SIBO) treatment is more complex than just antibiotics alone and involves treating the underlying conditions and nutritional issues, while also providing herbal and nutritional support, including the elimination of bacteria’s main food source: refined sugars, carbs, and alcohols. Long-term dietary restriction of these refined carbohydrates will prevent the incidence of SIBO recurring; similar to candida regrowth, some people are more susceptible to bacterial regrowth.  Creating a lifestyle of healthier food choices that support the body will help reinforce the decision of eliminating refined carbohydrates. At the Healing Center, we treat SIBO in a variety of ways, each catered to the individual patient. Treatment options include nutritional and dietary changes, supplements, and our frequency machine that eliminates pathogenic bacteria overgrowth.





Lipski, Elizabeth. Digestive Wellness: Strengthen the Immune System and Prevent Disease through Healthy Digestion. New York, NY: McGraw-Hill, 2012. Pgs:81-83. Print.


One response to “Abdominal Pain, Fatigue, Constipation, Diarrhea: Could your symptoms be from Small Intestinal Bacteria Overgrowth (SIBO)?”

  1. jenny

    excellent Jessica!!

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