Up until the end of the 20th century the small intestine was considered to be the “black box” for gastroenterologists. Th is was due to the impossibility of complete endoscopic visualization by non-surgical means. Its length and anatomically indeterminate position permits elongation of the small intestine by as much as 300%, resulting in the forma-tion of loops. Initial endoscopic studies such as Push Enteroscopy only allowed limited assessments of on average about 90cm of the small intestine (1). Th e enteroscopy probe was a long, complex and annoying procedure for patients and presented a 3% of per-foration risk (2, 3), as a result its use was abandoned. Intraoperative enteroscopy was long considered to be the gold standard for studying the small intestine. However, it is an invasive procedure with high risks since it requires general anesthesia and is a surgi-cal procedure (4, 5). Radiological methods for evaluating the small intestine have been characterized by their low sensitivity and specifi city, especially for obscure or hidden gastrointestinal bleeding (6, 7) usually caused by small vascular lesions. In the 21st Century several techniques have revolutionized study of the small intes-tine. Th ey include: video capsule endoscopy, double-balloon enteroscopy (9), single-balloon enteroscopy (10), and recently spiral enteroscopy (11). Th ese new technolo-gies have resulted in a huge advance in therapeutic and diagnostic effi cacy for diseases of the small intestine. Studies by Doctors Ospina and Villamizar show the experience in small intestine assessment in a Colombian hospital with single-balloon enteroscopy (12). Even though the number of patients studied is small, the results are important contributions to the knowledge of small intestine pathologies in our population. First of all, 93% of the patients had the presence of a obscure gastrointestinal hemorrhage as an exam indicator (27 patients). In 21 of these cases (72%) the indication was urgent clinically manifested dark bleeding. Th ese data are similar to the ones published in the literature (13, 14). Diagnostic performance for hidde n hemorrhages was about 80%. Th is result agrees with those in European and Asian publications where they have found a diagnostic effi cacy of 70-80% with double-balloon enteroscopy (14, 15). It should be noted that the study managed to achieve a complete visualization of the enteric mucosae in two patients using an approach combining single balloon enteroscopy combined with previous tatt oo with sterile Indian ink. Th is confi rms that single-balloon enteroscopies can also make a complete small intestine assessment. Even so, it has been shown that a full assessment is more likely with a double-balloon enteroscopy (18). It is probable that the high diag-nostic performance found in this study is due to the fact that most of the patients had clinically active bleeding, mentioned by the authors as urgent cases of occult bleeding.