Small Intestinal Bacterial Overgrowth (SIBO) is most frequently associated with malabsorption syndromes resulting from an overgrowth of bacteria in the small bowel. Many risk factors exist for the development of SIBO, such as altered anatomy from surgery, diabetes, small bowel strictures, advanced age, medications that lower gastric acid and chronic pancreatitis, among many others. Often the diagnosis of SIBO is not apparent, as the features of the preexisting conditions may be dominant and distract the clinician from other possibilities.
Steatorrhea
Steatorrhea is an increased amount of fat in the stool, a result of decreased lipid absorption in the bowels. Stools are frequently foul smelling, greasy in appearance and float, due to higher lipid contents.
Vitamin B12 Deficiency
This form of Vitamin B12 deficiency is often unresponsive to intrinsic factor therapy and is due to overgrowth in the terminal ileum, where B12 is normally absorbed. Neurologic signs can be present such as parasthesias, numbness, decreased reflexes and other signs of central or peripheral neuropathies. Anemic symptoms are also possible, such as shortness of breath and fatigue.
Bone Disease
Metabolic bone disease, especially osteoporosis, is a complication of the malabsorption syndrome that is well recognized by most physicians. Vitamin D is fat soluble and thus is excreted with the other lipids in the stool before full absorption can occur.
Night Blindness
Similar to Vitamin D, Vitamin A is fat soluble and has many effects in the body. It is utilized by the eye, especially, and night blindness is a common result of Vitamin A deficiency due to decreased absorption.
Coagulopathy
A tendency to bleed can also result if malabsorption continues chronically due to malabsorption of Vitamin K. Vitamin K is fat soluble and a necessary cofactor in the production of numerous clotting factors in the liver. Without it, the body's ability to clot is impaired.
Gastrointestinal Symptoms
Diarrhea, bloating, flatulence and abdominal discomfort are very common in patients with SIBO. This is usually a result of the products not being absorbed remaining in the GI tract, causing symptoms before being excreted.
Asymptomatic
Many people have been shown to have bacterial overgrowth with no presenting symptoms. In the absence of a malabsorption syndrome or other significant symptoms, "asymptomatic SIBO" is usually referred to as "simple colonization."
Diagnosis
If any questions remain, always consult a licensed health care provider. Only they have the training to evaluate the patient properly to come to the proper diagnosis; the symptoms above can occur with lots of different disease processes so care must be taken to not make presumptive "home diagnosis."
References
- "Sleisenger & Fordtran's Gastrointestinal and Liver Disease, 8th ed;" Feldman; 2006
- "Mandell, Douglas, and Bennett's Principles and Practice of Infectious Disease;" Mandell; 2009
- Pediatric Clinics of North America. "Nutritional Deficiencies in Intestinal Failure." Mziray-Andrew C, Sentongo T. Volume 56, Issue 5 (October 2009)
