A diabetic with dysfunction of the autonomic nervous system may develop an intermittent diarrhea that can last for years and cause significant distress.


Mechanism: Multiple mechanisms proposed, many resulting in gut dysmotility. Some patients have evidence of bacterial overgrowth.


The condition is often intermittent, separated by periods of normal bowel activity or constipation. Episodes may last from hours to days. Occasional patients may have a continuous disorder.


Clinical features of the episodes:

(1) The patient experiences attacks of watery diarrhea.

(2) Borborygmi and/or discomfort may precede the onset of diarrhea.

(3) Bleeding and pain are absent during the episodes.

(4) Most patients do not have evidence of malabsorption.

(5) Fecal incontinence may be worse at night.


Patient at risk:

(1) longstanding insulin-dependent diabetes

(2) gustatory sweating, postural hypotension or other symptoms of autonomic dysfunction



(1) It is important to exclude other causes of diarrhea (celiac disease, giardiasis, pancreatic malabsorption, etc.).

(2) One or more tests of autonomic function should be abnormal. The absence of autonomic dysfunction excludes the diagnosis.

(3) Trial of oral tetracycline therapy (to reduce bacterial overgrowth).


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