title: The role of gastrointestinal endoscopy in long-distance runners with gastrointestinal symptoms.
abstract: BACKGROUND
  Exercise-related gastrointestinal symptoms are not uncommon among athletes. The occurrence of gastrointestinal bleeding has been reported, especially in long-distance runners. We studied gastrointestinal mucosal damage, using gastrointestinal endoscopy, in competitive long-distance runners. Gastrointestinal blood loss and anaemia before and after running were also assessed.
  
  
  METHODS
  Sixteen competitive long-distance runners (all men; age range 16-19 years) participated in the study. All runners completed a symptom questionnaire prior to a 20 km race. Stool occult blood and haematological studies (haemoglobin, haematocrit, serum iron, total iron-binding capacity [TIBC] and ferritin) were performed before and immediately after the race. Gastrointestinal endoscopy was performed to assess macroscopic changes. Colonoscopy was also performed on the patients who had positive stool occult blood before or after the race.
  
  
  RESULTS
  Gastrointestinal symptoms were frequently experienced by the runners. Gastritis (n = 16), oesophagitis (n = 6) and gastric ulcer (n = 1) were found at gastroscopy. Colonoscopy was performed on four patients who had positive stool occult blood. One had multiple erosions at the splenic flexure and one had a rectal polyp. Five runners had anaemia, and all of these had at least one endoscopic lesion (three gastritis, two oesophagitis and one multiple erosion at the splenic flexure). There were significant changes in the following haematological parameters after the race: iron (decreased, P = 0.02), ferritin (decreased, P = 0.001) and TIBC (increased, P = 0.00005).
  
  
  CONCLUSIONS
  Gastrointestinal symptoms and gastrointestinal mucosal damage are prevalent among long-distance runners. Prior to treatment, gastrointestinal endoscopy should be considered in long-distance runners with gastrointestinal symptoms and/or anaemia.
authors.affiliation: Department of Gastroenterology, Wonkwang University School of Medicine and Wonkwang Health Science College, Iksan, Korea.
authors.forename: S C
authors.initials: SC
authors.lastname: Choi
authors.forename: S J
authors.initials: SJ
authors.lastname: Choi
authors.forename: J A
authors.initials: JA
authors.lastname: Kim
authors.forename: T H
authors.initials: TH
authors.lastname: Kim
authors.forename: Y H
authors.initials: YH
authors.lastname: Nah
authors.forename: E
authors.initials: E
authors.lastname: Yazaki
authors.forename: D F
authors.initials: DF
authors.lastname: Evans
mesh_terms: D000293:Adolescent; D000328:Adult; D000740:Anemia / Q000175:diagnosis; D016099:Endoscopy, Gastrointestinal / Q000379:methods* / Q000706:statistics & numerical data; D005500:Follow-Up Studies; D005753:Gastric Mucosa / Q000473:pathology; D005767:Gastrointestinal Diseases / Q000175:diagnosis* / Q000209:etiology*; D006801:Humans; D008297:Male; D009780:Occult Blood; D011446:Prospective Studies; D018570:Risk Assessment; D012420:Running / Q000293:injuries* / Q000502:physiology*; D012680:Sensitivity and Specificity