What are the signs and symptoms of SIBO?
There are no specific complaints or physical findings that can make the diagnosis of SIBO. Instead, small intestine bacterial overgrowth should be considered in the presence of a compilation of many non-specific symptoms; each by themselves would not be worrisome but together can point to the potential diagnosis.
Initial symptoms are specific to the gastrointestinal tract and abdomen and include:
- abdominal pain,
- diarrhea, and
- excess gas or flatulence.
A person with SIBO does not need to have all of these symptoms.
As the disease progresses, the bacterial overgrowth inhibits the body's ability to properly absorb nutrients from the diet. This can lead to vitamin and electrolyte abnormalities, protein deficiencies, and difficulties with fat absorption.
Inability to absorb vitamin B12 can lead to symptoms of pernicious anemia, including a low red blood cell count and peripheral neuropathy. Anemia also may be due to iron deficiency. Decreased Vitamin A may lead to night blindness. Metabolic bone disease may be due to Vitamin D deficiency and decreased calcium. This may also lead to muscle twitching and spasms.
Malnutrition may result in weight loss, and progress to excessive muscle wasting (cachexia). Inability to absorb fats in the diet may lead to steatorrhea (excess fat in the feces) that results in foul smelling oily stool, and may cause some anal leakage or fecal incontinence.