Spread of steroid-containing foam after intrarectal administration.

The spread of a steroid-containing foam from the rectum was studied in eight normal controls and eight patients with ulcerative colitis proved by biopsy. A standard dose of foam was labelled with technetium-99m adsorbed on to microspheres of Amberlite resin. Immediately after the foam was administered the extent of spread varied considerably, though in no instance did it extend beyond the rectosigmoid. Further scans at 120 and 240 minutes showed no further spread. It is concluded that a steroid-containing foam has a topical effect only on the rectal mucosa.