A 15-year-old boy was admitted to the hospital due to ataxia, drowsiness and bradypsychia. He was known to have a short bowel syndrome Initial venous blood gases revealed a metabolic acidosis with a high anion gap of 24 mmol/L and normal L-lactate. He improved with fasting and fluids and was discharged with oral metronidazole. 2 weeks later he was admitted again with similar symptoms. A specific study of D-Lactic acidosis was carried out, confirming the diagnosis. D-lactic acidosis is an uncommon complication of short bowel syndrome. It occurs as a consequence of the metabolism of unabsorbed carbohydrates. The symptoms are mainly neurological. Limiting the dietary carbohydrates is useful to avoid recurrences. Poorly absorbable antibiotics are used but with varying results. Surgery may be an option if medical treatment fails. Probiotics might be useful to avoid symthoms recurrence.