[Dementia caused by bacterial overgrowth in a patient with Billroth II gastrectomy].

We report the case of a patient in the Psychiatric Department who complained of progressive impairment of cerebral functions consistent with dementia, diarrhea and fecal incontinence in the last few months. His medical history included a Billroth II gastrectomy for gastric ulcer. Biochemical tests detected cobalamin deficiency, without megaloblastic anemia, and an abnormal Schilling test that was not due to intrinsic factor deficiency. Once other causes of cobalamin deficiency were ruled out, we considered it as a deficiency disease due to blind loop syndrome. Treatment with parenteral vitamin B complex and long term oral antibiotic therapy allowed the complete and permanent resolution of neurologic and digestive symptoms. We consider this case to be interesting because it shows the existence of curable dementias and the usefulness of taking into account bacterial overgrowth, usually underestimated, as an entity that can produce a variety of disorders.