[Lower digestive hemorrhage. Its etiology and the diagnostic efficacy of different explorations. A study of 2646 patients].

Lower gastrointestinal bleeding (LGB) is more frequent than upper gastrointestinal bleeding (UGB) with a better course and a more difficult diagnosis. We reviewed retrospectively 8544 cases from patients who were admitted at the Coloproctology Unit of Hospital de la Princesa. Those with the diagnosis of LGB with visible blood in stools (2646-31%) were outpatients, with a mean age of 43 years (range 9-91). Males represented 56.4% and females 43.6. All of them underwent at least sigmoidoscopic examination. The more frequent disorder was hemorrhoids (48.5%) and the bleeding source was found in the anus in 61%. Most of lesions (86%) could be reached with the short colonoscope and 92.7% of the bleeding sources were found with total colonoscopy. In 7.3% colonoscopy was not diagnostic and fiber gastroscopy identified the bleeding spot in 1.5% of the total. Barium studies were diagnostic in 0.5%, arteriography in 0.25% and radionuclide bleeding scan in 0.1%. Finally in 130 patients the bleeding source could not be found. We conclude that most of hemorrhagic lesions occur in the descending colon and that total colonoscopy can localize more than 92%. When total colonoscopy fails only 33% of the lesions can be found (2.35% from total) and 19% (1.5% from the total number) with UGB are identified with the fiber gastroscopic examination.