Diagnostic features

• Recurrent episodes of binge eating: objectively large amounts with a sense of loss of control.
• Recurrent inappropriate compensatory behaviours to prevent weight gain (self‑induced vomiting, misuse of laxatives/diuretics, fasting, or excessive exercise).
• Behaviour occurs on average ≥1 episode/week for 3 months (DSM‑5); self‑evaluation is unduly influenced by body shape and weight.
• Differentiate from BED (no compensatory behaviour) and OSFED/purging disorder when binges are absent.

Clinical features & consequences

• Psychological: shame, guilt, mood lability, perfectionism, and high rates of comorbid depression, anxiety and substance misuse.
• Medical: dental erosion, parotid enlargement, oesophageal tears, hypokalaemia, metabolic alkalosis, dehydration, constipation, menstrual irregularities and cardiac arrhythmias.
• Functional: impaired social and occupational functioning, secrecy around eating, and financial burden from food and purging behaviours.

Screening & assessment

1. Targeted eating history: binge frequency, size, triggers, compensatory methods, laxative/diuretic use, frequency of purging and impact on daily life.
2. Medical screen: vitals, weight, orthostatics, dental exam, electrolytes (K+, Cl−), acid‑base status, renal function and ECG when indicated.
3. Mental health assessment: suicidality, mood disorders, impulsivity, substance use and personality factors; use EDE‑Q or SCOFF as screening tools.

First‑line psychological treatments

• CBT‑E (enhanced cognitive behavioural therapy): first‑line for bulimia — focuses on normalising eating patterns (regular meals), reducing dietary restraint, addressing overvaluation of weight/shape and relapse prevention.
• Interpersonal Psychotherapy (IPT): effective alternative focusing on interpersonal problems that maintain binge‑purge cycle; may be offered when CBT‑E unavailable or less acceptable.
• DBT‑informed approaches: useful when emotion dysregulation or impulsivity contributes to bingeing and purging.

Pharmacologic treatments

• Fluoxetine 60 mg daily is the only medication with robust evidence and regulatory approval for BN in many jurisdictions—reduces binge/purge frequency and improves mood; start at lower dose and titrate with monitoring.
• Other SSRIs may help comorbid depression/anxiety; monitor for side effects and interactions.
• Medication is adjunctive to psychotherapy; for severe cases combine pharmacotherapy with CBT‑E for best outcomes.

Medical management & monitoring

• Correct electrolyte disturbances, rehydrate, manage oesophageal or dental complications; monitor for hypokalaemia and arrhythmia in purging patients.
• Reduce laxative/diuretic misuse with gradual taper, medical monitoring and behavioural strategies; involve nephrology if prolonged electrolyte disturbance.
• Coordinate dental care for erosion and ENT/gastroenterology for oesophageal injury when indicated.

When to refer

• Refer to specialist eating‑disorder teams for severe medical complications, persistent binge/purge despite outpatient therapy, significant comorbidity (substance misuse, severe depression), or diagnostic uncertainty.
• Consider inpatient or day‑programmes for medical stabilization or when outpatient engagement is insufficient.

Key takeaways

• Bulimia nervosa involves recurrent binge eating with compensatory behaviours and carries medical and psychological risks but responds well to CBT‑E and fluoxetine (adjunct).
• Perform medical screening for electrolyte and cardiac complications in purging patients and manage these urgently when present.
• Coordinate care between psychiatry, dietetics, dentistry and medical teams; monitor safety and suicidality closely.