Barium enema after colorectal biopsies: experimental data.

The appropriate interval between a colorectal biopsy and a barium enema is controversial. Superficial and deep biopsies, above and below the peritoneal reflection, were performed on 12 dogs. Six control dogs did not have a barium enema. Six study dogs had a barium enema at different postbiopsy time intervals: immediately, 3 days, and 6 days. After superficial biopsies, there was no barium extravasation in any study animal. Histological examination, 48 hr after enema, showed complete epithelialization of all superficial sites on both study and control dogs. When the barium enema was done after a deep biopsy, there was intramural extravasation of barium immediately after biopsy but not after 3 or 6 days. Focal ulcerations were seen microscopically at sites of deep biopsies when the barium enema was performed immediately and 3 days after the diagnostic procedure. All deep biopsy sites were reepithelialized in 6 days. There was no evidence of intraperitoneal or retroperitoneal perforation and no difference in healing of biopsy sites in subjects and control animals. This study in dogs suggests that a barium enema may be performed without hazard immediately after a superficial biopsy of nondiseased colon and 6 days after a deep biopsy.