The reasoning
Recurrent binges (objectively large intake + loss of control) + recurrent inappropriate compensation (self‑induced vomiting, laxatives/diuretics, fasting, excessive exercise), with self‑evaluation unduly influenced by weight/shape. Weight is typically normal or above — so weight cannot exclude the diagnosis.
The medical footprint (often the presenting clue) 🚩
- Vomiting/purging: hypokalaemia, hypochloraemic metabolic alkalosis, dental erosion, parotid hypertrophy, Russell's sign (knuckle callus), oesophagitis/Mallory‑Weiss.
- Laxative abuse: metabolic acidosis, dehydration.
- Hypokalaemia → arrhythmia risk (the acute danger). Ipecac abuse → cardiomyopathy.
Management
Eating‑disorder‑focused CBT (CBT‑ED) is first‑line; fluoxetine (higher dose, e.g., 60 mg) is the antidepressant with the best evidence and reduces bingeing. Correct electrolytes; medication is not a sole treatment.
Discriminators
- Bulimia vs anorexia binge‑purge subtype: the latter is at significantly low weight.
- Bulimia vs BED: presence of compensatory behaviour.
Pitfalls
- Excluding an eating disorder because the patient isn't underweight.
- Missing hypokalaemia.
Pearls
- 🎯 Normal weight does not exclude a serious eating disorder.
- 🩺 Check K⁺ and look for Russell's sign/dental erosion — the body tells the story.
Next → Binge eating without compensation, and pica (Concept 35).