A device for delivering a dose of medicament comprising activated carbon particles to a patient's rectal cavity has a rectally-insertable cannula. The cannula has a proximal opening, a distal opening and a cavity defined between the proximal and distal openings for containing the medicament. An openable closure spans the proximal opening of the cannula. An actuation means is arranged to drive a volume of fluid, for example water or air, through the cannula cavity to flush the dose of medicament through the distal opening of the cannula.
