Synopsis
Differentiate early and late dumping, nutritional deficiency, bile reflux, marginal ulcer and mechanical complications after gastric surgery, and act urgently on obstruction, internal hernia, bleeding or thiamine deficiency.
- Establish the exact operation and reconstruction: total or partial gastrectomy, sleeve, Roux-en-Y bypass, anastomoses, vagotomy and small-bowel limb lengths create different physiology and hazards.
- Early dumping occurs during or soon after eating through rapid hyperosmolar delivery, causing abdominal symptoms, flushing, tachycardia and faintness; late dumping one to three hours later is predominantly reactive hypoglycaemia.
- Persistent vomiting, food sticking, severe focal pain, gastrointestinal bleeding or pain after Roux-en-Y can indicate stricture, ulcer, internal hernia or obstruction and needs anatomical investigation.
- After total gastrectomy or bypass, vitamin B12, iron, folate, vitamin D, calcium and other micronutrient deficiencies require lifelong surveillance and procedure-specific supplementation.
- Neuropathy, confusion, ataxia or eye-movement abnormality after repeated vomiting is thiamine deficiency until treated; give urgent parenteral thiamine before carbohydrate.
- Diet is first-line for dumping: small frequent meals, reduce rapidly absorbed carbohydrate, separate most drinks from meals and include protein and fibre with specialist dietetic support.
- Bile reflux, pancreatic insufficiency, small-intestinal bacterial overgrowth and altered drug absorption can coexist, so response to one empirical treatment does not define the syndrome.
- Avoid modified-release or enteric-coated assumptions after bypass and review every medicine with pharmacy; NSAIDs can increase marginal-ulcer risk.
Key red flags
Sweating, tremor, hunger, aggression, cognitive change or collapse one to three hours after food suggests postprandial hyperinsulinaemic hypoglycaemia. Severe neuroglycopenia is an emergency.
Progressive dysphagia, persistent vomiting, focal or colicky pain, distension, tachycardia, peritonism or an obstructive pattern years after bypass raises anastomotic stricture, internal hernia or small-bowel obstruction.
Epigastric pain, nocturnal reflux, haematemesis, melaena or iron deficiency may reflect bile reflux, marginal ulcer, anastomotic disease or recurrent malignancy and requires endoscopic assessment.
Ataxia, confusion, ophthalmoplegia, neuropathy, cognitive change or weakness with vomiting or poor intake suggests thiamine, B12, copper or vitamin E deficiency; treat time-critical thiamine immediately.
Investigation priorities
Obtain the operative report, reconstruction, limb lengths, complications and follow-up plan; record meal composition, symptom timing, stool, vomiting, medicines and weight trajectory.
Management branches
Vasomotor or gastrointestinal symptoms occur reproducibly during or after meals without an acute surgical alarm.
- Map symptom timing and composition, document glucose during late episodes and review diabetes medicines, alcohol and endocrine alternatives.
- Refer to an experienced dietitian for small frequent protein-containing meals, reduced rapidly absorbed carbohydrate, slower eating and separation of drinks from solids.
- Escalate persistent late hypoglycaemia for specialist acarbose or other therapy and driving or occupational safety advice.
- Reconsider anatomy, ulcer, pancreatic insufficiency or another diagnosis when structured diet does not improve the expected phenotype.