Depth of colorectal biopsies with proctoscopic forceps

It has been suggested that a barium enema may safely follow a colorectal biopsy superficial to the muscularis propria within 24 hours, but that the colon radiograph should be postponed 3 to 7 days following a biopsy including this layer. The authors prospectively studied 67 colorectal biopsies obtained with the Wolf 3-mm (grasping) and 5-mm (cutting) proctoscopic forceps from 49 patients to determine the depth of the biopsies. The 5-mm biopsies were not significantly deeper than the 3-mm biopsies (p greater than 0.5). In 18 patients biopsied with each instrument, the 3-mm biopsy was deeper in two cases (11%), the 5-mm biopsy was deeper in three cases (17%), and the biopsies were of equal depth in 13 cases (72%). None of the biopsies with either forceps reached the muscularis propria. The authors concluded that it may be unnecessary to wait longer than 24 hours before performing a barium enema after colorectal biopsy with these forceps.