Comparison of fecal blood loss after use of aspirin and diflunisal.

Diflunisal 1,000 mg/day, aspirin 4.0 g/day, or placebo were given to 36 healthy volunteers for 14 days to determine fecal blood loss. There was a significant increase in fecal blood loss from baseline in the aspirin group compared to both the diflunisal and placebo groups. A slight but significant increase in fecal blood loss in the diflunisal group at Week 1 was reported; however, there was no significant increase at Week 2. Use of diflunisal was not associated with any consistent blood loss or serious adverse reactions.