Fourteen patients with severe and persistent postvagotomy/postgastrectomy symptoms were entered into a trial of treatment with the somatostatin analogue octreotide, 50 micrograms twice daily 30 min before meals being self-administered by subcutaneous injection. Six of the seven patients completing the 3-month trial showed sustained overall improvement of symptoms. The remaining patients were unhelped by treatment or developed unwanted effects. Six of eight patients with dumping syndrome showed sustained improvement of dumping symptoms during treatment. Bile vomiting was relieved in three of four patients with this complaint. Diarrhoea accompanying dumping showed a variable response to treatment, with improvement in three patients and no change or worsening of this symptom in five. Two patients with severe postvagotomy diarrhoea alone showed no improvement. Four patients with unwanted effects and three patients who found no benefit stopped the trial medication early. Four further patients reported mild or transient side-effects. For patients with severe postvagotomy/postgastrectomy symptoms, a trial of octreotide seems justified when significant dumping symptoms are present and other treatment options have been exhausted.