Barium enemas are a headache.

The frequency of headache after Picolax (sodium picosulphate, Nordic Ltd) preparation for barium enema was investigated and its association with dehydration, as assessed by haemoconcentration, was determined. Eleven out of 41 patients (26.8%) complained specifically of headaches. Although patients with and without headaches developed significant increases in haemoglobin concentration after Picolax preparation, the rise in haemoglobin in those with headaches was significantly greater than in those without (P less than 0.05). In both groups the haemoglobin concentration returned to normal after a bowel washout. These results suggest an association between dehydration and headache developing after a Picolax regimen. It may be possible to prevent this symptom by advising on the intake of specific volumes of fluid during preparation for barium enema.