The clinical and laboratory findings of 290 cases of bloody diarrhea who presented to the department of Diarrhea Training and Treatment between June 1998 and May 2002 were investigated, and compared to those of two consecutive cases who had watery diarrhea. The bloody diarrhea group had higher mean age, higher frequencies of diarrhea, lower frequencies of vomiting, and shorter durations of diarrhea at the time of admission as compared to the watery diarrhea group. The number of cases using antibiotics before the onset of diarrheal attacks was higher in the bloody diarrhea group, and sulbactam-ampicillin had been used more frequently in this group. The presence of dehydration was similar in the two groups, but the occurrence of moderate to severe dehydration was significantly less in the bloody diarrhea group. Salmonella was the most common enteropathogen in the bloody diarrhea group; however, isolation of shigella was similar in both groups. In the bloody diarrhea group, one had convulsion, one rectal prolapse, and one intussusception. The rates of hospitalization and antibiotic use were higher in the bloody diarrhea group. The use of antibiotics should be evaluated in cases with bloody diarrhea. Further studies are necessary to detect changes in the pathogens responsible for bloody diarrhea in developing and developed countries.