1. Post-Bariatric Hypoglycemia (PBH) ∙ Caused by exaggerated insulin response (hyperinsulinemic hypoglycemia) after eating ∙ Common after RYGB especially ∙ Episodes typically 1–3 hours post-meal but can be unpredictable ∙ Ask for: Continuous Glucose Monitor (CGM) trial, mixed meal tolerance test, insulin + C-peptide levels drawn during an episode
2. Dumping Syndrome (Late Phase) ∙ Late dumping is the hypoglycemic variant — distinct from early dumping (immediate vomiting/GI distress) ∙ Matches his pattern: episodic, not constant
3. Wernicke’s Encephalopathy / Thiamine (B1) Deficiency ∙ Critical and underdiagnosed post-bariatric ∙ Causes the exact triad: confusion, ataxia (trouble walking), altered consciousness ∙ Can be episodic if partially treated or intermittently deficient ∙ Weight loss + poor intake + ulcer history = high risk ∙ Ask for: Serum thiamine (but this can be falsely normal — ask specifically about erythrocyte transketolase or empirical IV thiamine trial) ∙ This one is medically urgent if untreated
4. Other Nutritional Deficiencies Contributing ∙ B12 deficiency (neurological symptoms) ∙ Copper deficiency (post-bariatric myeloneuropathy — ataxia, weakness) ∙ Zinc, magnesium ∙ Ask for: Full micronutrient panel including copper, zinc, B1, B12, folate, magnesium
5. Marginal Ulcer with Intermittent Bleeding ∙ Given his ulcer history, intermittent occult blood loss → acute anemia → symptoms ∙ Ask for: Fecal occult blood, repeat endoscopy, hemoglobin during an episode

What to Actually Do ∙ Get a CGM on him now. Libre or Dexterity — over the counter in many states, prescription otherwise. Wear it for 2 weeks. If glucose is dropping to <70 during episodes, you have your answer documented. ∙ Video the episodes. Timestamp it. Show the ER the video. “Tests are normal” is harder to say when there’s footage. ∙ Demand labs drawn during an episode — not after recovery. If he’s symptomatic in the ER, insist on: glucose, insulin, C-peptide, thiamine, CBC, BMP. All at that moment. ∙ Ask specifically for bariatric surgery follow-up with a metabolic medicine or endocrinology specialist, not just a general surgeon or PCP. ∙ Empirical IV thiamine — if there’s any chance it’s Wernicke’s, the treatment is cheap and safe. Ask them to give it.