Nonfatal Hyperammonemic Encephalopathy as a Late Complication of Roux-en-Y Gastric Bypass.

Roux-en-Y gastric bypass (RYGB) is the most common weight loss procedure performed in the US. Gastric bypass-related hyperammonemia (GaBHA) is a potentially fatal entity, characterized by encephalopathy associated with hyperammonemia and various nutritional deficiencies, which can present at variable time intervals after RYGB. Twenty-five cases of hyperammonemic encephalopathy after bariatric surgery have been previously reported in the literature.