Why do bacteria multiply in the small intestine?
The small intestine is protected by several barriers. The hydrochloric acid of the stomach neutralizes most microbes, bile and pancreatic enzymes suppress their growth, and special waves of contractions between meals sweep the remaining contents forward. Violation of any link opens the way to excess growth. Therefore, SIBO often occurs after operations on the stomach and intestines, with adhesions and narrowings, diverticula of the small intestine, with diabetes mellitus with nerve damage, scleroderma, and also against the background of many years of taking drugs that reduce acidity.
- Reduced stomach acidity
- Stomach and intestinal surgeries
- Adhesions and narrowing of the small intestine
- Small intestinal diverticula
- Slow motor skills in diabetes and scleroderma
- Pancreatic insufficiency
- Ileocecal valve dysfunction
Symptoms
The most common complaint is bloating, which increases throughout the day and gets worse after eating, especially after foods rich in carbohydrates. Characterized by rumbling, increased gas formation, a feeling of fullness, unstable stools with alternating diarrhea and constipation. With a long course, absorption is impaired: a deficiency of vitamin B12, fat-soluble vitamins and iron develops, weakness, brittle nails, tingling in the fingers appear, and the stool becomes greasy. Many patients are treated for years for irritable bowel syndrome because the complaints are very similar.
- Bloating, worse in the evening
- Rumbling and increased gas formation
- Feeling full after eating
- Unstable chair
- Vitamin B12 and iron deficiency
- Fatty stools with severe malabsorption
Diagnostics
The most accessible method is a hydrogen breath test with lactulose or glucose: after taking the solution, the hydrogen content in the exhaled air is measured, and an early rise indicates bacterial fermentation in the small intestine. The method is not ideal and requires proper preparation: certain foods are excluded the day before, and antibiotics are canceled in advance on the recommendation of a doctor. It is equally important to look for the cause: perform gastroscopy, ultrasound of the abdominal cavity, evaluate pancreatic function, exclude celiac disease and inflammatory bowel diseases. Vitamin B12, folic acid, iron and complete blood count are checked.
- Hydrogen breath test with proper preparation
- Complete blood count, vitamin B12, folic acid, iron
- Coprogram and fecal elastase
- Gastroscopy and ultrasound of the abdominal cavity
- Rule out celiac disease and inflammatory bowel disease
- Assessment of previous operations and adhesions
Treatment
The basis of therapy is short courses of antibacterial drugs acting primarily in the intestinal lumen; the choice and duration are determined by the doctor. At the same time, they adjust their diet: temporarily limit foods that increase fermentation, maintain intervals between meals so that the cleansing waves of peristalsis work, and do not snack constantly. If motor skills are impaired, medications that improve the movement of contents are discussed. Be sure to replenish vitamin deficiencies. The main condition for a long-term result is the elimination or control of the underlying cause, otherwise bacterial growth will resume in a few months.
- Antibacterial therapy as prescribed by a doctor
- Temporary restriction of foods that enhance fermentation
- Pauses between meals without snacking
- Drugs that improve motility, when indicated
- Replenishment of vitamin B12 and iron deficiency
- Enzyme preparations for pancreatic insufficiency
- Treatment of the underlying disease
How is it different from other conditions?
SIBO can easily be confused with irritable bowel syndrome, lactose intolerance, celiac disease and functional bloating: the complaints overlap in many ways. Relationships with previous surgeries and diseases that alter motility, the presence of signs of impaired absorption and the result of a breath test help to distinguish. It is important not to diagnose yourself and not to take courses of antibiotics based on advice from the Internet: they temporarily reduce bloating, but if the diagnosis is incorrect, they harm the microflora and delay the identification of the real cause, including serious intestinal diseases.
- Irritable bowel syndrome
- Lactose and fructose intolerance
- Celiac disease
- Pancreatic insufficiency
- Inflammatory bowel diseases
- Functional bloating