Gastrointestinal Beriberi Secondary to Intermittent Hemodialysis With Rapid Improvement Following Thiamine Administration.

Thiamine deficiency is classically linked to malnutrition and chronic alcohol use, but emerging evidence indicates that patients on intermittent hemodialysis (iHD) are also at significant risk. While cardiovascular and neurologic syndromes are well characterized, gastrointestinal (GI) beriberi remains an underrecognized presentation. We describe a 67-year-old man on iHD with chronic abdominal pain, nausea, vomiting, and anorexia refractory to conventional therapy. Workup revealed elevated lactate and a low plasma thiamine level prior to supplementation. Symptoms and elevated lactate resolved rapidly following intravenous thiamine. This case underscores GI beriberi as a treatable cause of chronic GI symptoms in dialysis patients.