Small intestinal bacterial overgrowth is a health problem in which very large numbers of bacteria grow in the small intestine; Jejunum and ileum. The Symptoms of this condition are non-specific in the early stages, but may include indigestion, diarrhea, abdominal pain, and bloating.

Several diagnostic procedures are available to confirm (SIBO). They include blood tests, breath tests, and biopsies or tissue samples from the small intestine. Antibiotics may be prescribed to deal with the infection, but the type and length of treatment depends upon the patient and the symptoms.

The consequence of the condition, Small Intestinal Bacterial Overgrowth, depends upon how well the associated illnesses and symptoms are managed. Relapse is quite common and often depends also upon how well the underlying cause is controlled.

It is a condition characterized by increase bacterial number that normally exist in the upper digestive tract -including the stomach and small intestine- or reaching colon bacteria to the small intestine and proliferation of it, which could lead to inflammation and digestive symptoms and interfere with nutrient absorption.

There are microorganisms that live in the upper gastrointestinal tract in a nonpathogenic number, including lactobacilli, streptococci and enterococci. They are important for normal gastrointestinal function, but when they overgrow in some conditions or substituted by pathogenic types of bacteria they cause the condition of small intestinal bacterial overgrowth.

Some people have greater tendency to have this condition under the effect of illnesses and cases like:

• Immunodeficiency, such as AIDS patients and those treated with chemotherapy;
• Diseases that lead to movement problems in the small bowel, such as diabetes and scleroderma;
• Diverticular diseases, intestinal obstruction or blind loop syndrome that blocks or slowdown digested food passing through small intestine;
• Patients of acid-reducing substances or with deficiency of hydrochloric acid in the digestive juices in the stomach “achlorhydria”;
• Some cases of Irritable bowel syndrome and Crohn's disease;
• Undergoing surgical procedures and resection part of the intestine.

Bacteria exist normally at all parts of gastrointestinal tract. The greatest number located in the colon with more than 1 billion bacteria per ml of its fluid. Small intestine has much lesser amount with below than 10,000 bacteria per ml, also the types of bacteria differ between the small and large intestine.

Bacteria start to grow fast in small intestine when natural controlling mechanisms of bacterial growth are disrupted. The main two problems emerge from decreased intestinal motility and diminished stomach acid secretion. Disturbances in gut immune function and anatomical abnormalities of the GI tract also increase the likelihood of developing (SIBO). Once present, bacterial overgrowth may induce an inflammatory response in the intestinal mucosa, further exacerbating the typical symptoms of the condition.

Most patients of bacterial overgrowth syndrome are a symptomatic and may only demonstrate mild degree of nutritional deficiencies. However, some affected persons may have digestive symptoms includes:

• Abdominal pain and cramps;
• Bloating and flatulence;
• Diarrhea, occasionally as “steatorrhea”.

Another sign and symptoms may appear in severe cases as a result of dehydration and inadequate nutrition intake. For instance, Iron and vitamin B12 deficiency anemia could cause fatigue and poor concentration.

The First step in managing this condition is by appropriate history taking and physical examination. The doctor looking for signs and symptoms and asking about etiologic causes, such as history of surgical procedures in the gastrointestinal tract that may point toward the diagnosis. Some tests that done to insure the problem:

• Bacterial count in small intestine, which is recognized as the best diagnostic method of small intestinal bacterial overgrowth when bacteria exceed 105 per ml in fluid samples;
• D-xylose test absorption, fecal fat test, also vitamins and minerals levels in the blood;
• Imaging procedures, like x-ray;
• Endoscopic evaluation with possible biopsies taken for histopathology and culture;
• Breath tests may be considered to measure the byproducts of digestion, especially those that are dependent upon bacteria in the intestine.

Dealing with this problem focuses on controlling and treating illnesses or conditions underlying small intestinal bacterial overgrowth. The goal is to control the symptoms of the condition since it may not be possible to "cure" the disease. The treatment includes:

• “Amoxicillin-Clavulanate”, “zifamaxin” are considered the first line antibiotic drugs for controlling this condition. This approach of treatment may include other types like ciprofloxacin and metronidazole;
• Compensation of fluid and nutrients that are required to the body, even orally or intravenously;
• A low-carbohydrate diet, especially low-sugar, can help to decrease bacterial growth in the small intestine.

Most cases of small intestinal bacterial overgrowth don’t lead to serious health problems, but sever cases may cause malabsorption, malnutrition, dehydration, vitamins and minerals deficiencies and could develops to acute renal injury and liver disease.

There are several natural mechanisms inside the body for preventing bacterial overgrowth, such as gastric acid secretion, intestinal motility, intact ileo-caecal valve, immunoglobulins within intestinal secretion and bacteriostatic properties of pancreatic and biliary secretion. Keeping these mechanisms working as should be will help protect basically from it or decrease the chances of recurrence.

The preventive approach depends on the risk factor threatens the person. Based on this, he may receive Supplement with Hydrochloric Acid (HCl), or encouraged to stop taking medications that decrease stomach acidity, like proton pump inhibitors (PPI's), and antacids. A prokinetic drug may be prescribed to enhance gastrointestinal motility. Dysfunction of ileo-caecal Valve may be corrected to restore the physical barrier to bacterial backflow from the large intestine.

Small intestine bacterial overgrowth is usually associated with another underlying illness. Even with appropriate treatment, the relapse rate is high and often depends upon how well the underlying illness is managed and controlled. As a result, while a single course of antibiotics for 1-2 weeks may be sufficient, sometimes repeated courses of antibiotics may be required. In some people, the antibiotics will be routinely cycled, meaning that they will alternate 1-2 weeks on the antibiotic with 1-2 weeks off.

The exact prevalence of bacterial overgrowth syndrome is usually underestimated because the sign and symptoms overlap with many other digestive disorders, such as malabsorption and diarrhea. There is no global statistics for the prevalence of this condition as it could vary depending on the population studied and the diagnostic methods used.