Symptoms & Causes
SIBO (Small Intestinal Bacterial Overgrowth)
What is SIBO (Small Intestinal Bacterial Overgrowth)?
What is SIBO (Small Intestinal Bacterial Overgrowth)?Small Intestinal Bacterial Overgrowth (SIBO) is a condition characterized by excess overgrowth of microflora in the small intestine resulting in gastrointestinal symptoms such as diarrhea and bloating. Your gut microbiome comprises trillions of gut bacteria in the large intestines. But in people with SIBO, large amounts of bacteria are present in the small intestine.
In general, most cases of SIBO occur in patients with risk factors such as a medical history of intestinal surgeries or radiation, strictures, celiac disease, diabetes, inflammatory bowel disease, scleroderma, or motility disorders.
Signs & Symptoms of SIBO
SymptomsPatients with SIBO have a range of symptoms that may overlap with other digestive conditions. As a result, it can be challenging to differentiate between SIBO and other digestive disorders. SIBO can also worsen other gastrointestinal (GI) conditions.
Symptoms of SIBO include:
- Abdominal bloating: Bloating is a common symptom of SIBO, and is reported by most patients.
- Flatulence: Having some gas is a normal part of the digestive process. But individuals with SIBO often experience excessive amounts of gas due to bacterial overgrowth.
- Diarrhea: The excess bacteria in the small intestine break down bile salts needed to digest fats. The result is incomplete digestion of fats resulting in malabsorption and diarrhea. Certain bacteria may also cause diarrhea through direct injury to the intestinal surface.
- Weight loss and fatigue: SIBO can lead to poor nutrient absorption, resulting in fatigue, weight loss, and vitamin deficiencies.
- Abdominal distension: Excess bacteria in the small intestine break down carbohydrates, resulting in methane and hydrogen gas production, causing uncomfortable gas, bloating, and abdominal pain.
- Foul-smelling stools: With SIBO, the bile acids used to absorb and break down fat may be deficient, causing malabsorption and resulting in greasy, oily, smelly, or floating stools.
If any of these symptoms affect you, rest assured that the specialists at NewYork-Presbyterian can help treat the most severe SIBO symptoms.
What Causes SIBO?
What Causes SIBO?The underlying cause of SIBO varies from patient to patient. Impaired intestinal motility may lead to stasis and reduced clearance of bacteria from the small bowel in disorders such as scleroderma and chronic intestinal pseudo-obstruction.
Anatomic abnormalities such as bariatric surgery, strictures, or adhesions may also result in stasis and bacterial overgrowth. Systemic disorders such as diabetes, pancreatic insufficiency, or immunodeficiencies such as human immunodeficiency virus (HIV) can also predispose to SIBO.
Medical conditions often associated with SIBO:
- Diabetes
- Celiac disease
- Bowel obstruction
- Scleroderma
- Chronic pancreatitis
- Cirrhosis of the liver
- Crohn's disease
- Intestinal surgery
- Nerve damage
- Certain gastric bypass procedures
- Irritable bowel syndrome
- Surgeries that cause strictures or adhesions
Conditions that may increase the risk of SIBO:
- Consuming a high carbohydrate diet which includes sugar
- Anatomic abnormalities in the small intestine
- A compromised immune system
- Food that moves too slowly or is stagnant when moving through the small intestine
Risk Factors
Risk FactorsSIBO can result from an imbalance in the small intestine's bacterial flora.
Various risk factors can contribute to the development of this GI condition, including:
- Celiac disease: An autoimmune condition in which gluten protein in food triggers a reaction that damages the lining of the small intestine. Untreated Celiac disease can cause long-term injury to the digestive tract, preventing the body from absorbing nutrients.
- Cirrhosis: Liver scarring caused by injury or disease such as chronic alcohol abuse, non-alcoholic fatty liver disease, viral hepatitis, or certain autoimmune and metabolic disorders. Common symptoms of cirrhosis include jaundice, weight loss, and muscle wasting.
- Crohn's disease: A form of Inflammatory Bowel Disease (IBD). The condition causes inflammation, strictures, and ulcers within the lining of the digestive tract and is commonly found in the small intestine.
- Diabetes: A chronic condition that affects the body's ability to manage blood sugar levels. With diabetes, the pancreas doesn't release enough insulin to help the body to use the glucose in food effectively.
- Gastroparesis: A disorder that causes delayed stomach emptying into the small intestine often found in patients with diabetes or may occur after certain gastrointestinal infections or after surgery. This condition is sometimes related to damage to the vagus nerve, which controls the motility of the stomach and small intestine.
- Hypothyroidism (underactive thyroid): A condition in which the thyroid, a small, butterfly-shaped gland in the front of the neck, doesn't produce enough thyroid hormones. Primary symptoms include sensitivity to cold temperatures, muscle cramps, constipation, and weight gain.
- Radiation enteritis: A complication of radiation therapy that can result in altered motility, inflammation, or strictures in the small intestine, resulting in SIBO and diarrhea.
- Scleroderma: A chronic autoimmune disease characterized by multisystem fibrosis which can cause impaired intestinal motility and predispose to SIBO.
- Previous medical treatments: Sometimes, medical procedures can contribute to SIBO. Altered anatomy from gastric bypass surgery, for instance, can result in blind loops and stasis of intestinal contents that predispose to SIBO.
- Immunodeficiency: The gut microbiome is home to trillions of microorganisms in your digestive tract. Disorders of immunodeficiency, such as human immunodeficiency virus (HIV), immunoglobin A (IgA), or common variable immunodeficiency, may predispose to bacterial overgrowth.
Complications
ComplicationsLiving with SIBO is challenging. When SIBO isn't well-controlled, individuals with the condition can experience severe diarrhea, flatulence, bloating, and sometimes nutritional deficiencies. As a result, complications may arise that can profoundly impact overall health.
Complications from SIBO include:
- Vitamin deficiency: Due to bacterial overgrowth in the small intestine, vitamins and minerals may not be properly absorbed. As a result, people with SIBO can experience weight loss, dizziness, fatigue, and muscle weakness. If you've been diagnosed with SIBO, talk to your doctor about multivitamins and mineral supplementation.
- Osteoporosis: The abnormal bacterial growth results in poor calcium absorption, which may eventually lead to bone diseases such as osteopenia. If left untreated, osteopenia can progress to osteoporosis and increase bone fracture risk.
- Kidney stones: Poor calcium absorption can also eventually lead to the production of kidney stones. Signs and symptoms of kidney stones include severe pain, vomiting, fever, chills, and blood in the urine.
Prevention
PreventionSIBO can recur even after treatment. It is important to address the underlying cause. Unfortunately, most disorders predisposing to SIBO do not have a cure. But with the help of a healthcare professional, you can develop a treatment program that can manage the underlying cause and reduce the chances of the condition returning.
Strategies for addressing SIBO recurrence include:
- Addressing structural problems: Sometimes, impaired GI motility can contribute to SIBO recurrence. For instance, adhesions and scar tissue can form after certain surgeries slowing down intestinal transit. Massaging the lower abdominal area, a technique called visceral manipulation performed by a physical therapist, may help improve GI transit by breaking up scar tissue.
- Adjusting medications: Sometimes, a medication used to treat a specific health problem can create conditions that predispose to SIBO. Narcotic pain medications (opiates) in particular, can impair gastrointestinal motility predisposing to SIBO. Adjusting or discontinuing these medications may help reduce SIBO symptoms.
- Addressing alcohol use: Excessive alcohol consumption can increase your risk of developing SIBO. Even consuming alcohol in small amounts can negatively affect the healthy bacteria in the large intestine (colon). Prevention and treating SIBO may mean limiting or, better yet, eliminating alcohol consumption.
- Adopting a low-carb diet/probiotics: FODMAPs (fermentable oligo-, di-, and monosaccharides and polyols) are carbohydrates that are poorly absorbed and rapidly fermented by intestinal bacteria. Limiting these foods may improve bloating and diarrhea. Probiotics may be helpful in some instances, but data to support their effectiveness in SIBO is limited.
Trust NewYork-Presbyterian for SIBO Care
Sometimes Small Intestinal Bacterial Overgrowth (SIBO) can mimic other medical conditions. Being aware of symptoms will help in ultimately diagnosing SIBO. Our experienced team of healthcare professionals is ready to help provide you with the necessary treatments. Give us a call today.