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Exercise-related gastrointestinal disorders

John H Kwon, MD, PhD
J Thomas Lamont, MD
Section Editor
Lawrence S Friedman, MD
Deputy Editor
Shilpa Grover, MD, MPH, AGAF


Exercise-related gastrointestinal symptoms can impact performance. Many of these symptoms are related to physiologic changes resulting from exercise [1,2]. Physiologic changes include alterations in enteric nervous system activity, circulating gut hormone levels, intestinal blood flow, nutrient and electrolyte absorption, intestinal secretion, and motility [1]. This topic review will discuss the most frequently observed gastrointestinal disorders that occur in athletes.


The incidence of exercise-induced gastrointestinal (GI) symptoms range from 20 to 96 percent [3-10]. The incidence is higher in women and in younger athletes [2,3]. Exercise-related gastrointestinal symptoms are frequently associated with consumption of a meal within two to three hours of exercising [3,5,11-14]. Dehydration and analgesic use are associated with a higher incidence of GI symptoms [15,16]. While some studies have found an association between the intensity of the exercise and the incidence of GI symptoms, results have been inconsistent [3,5,12,13,17,18].

GI symptoms vary with the type of exercise. In general, long-distance runners have a high incidence of lower GI symptoms (eg, fecal urgency, diarrhea, rectal bleeding), and transient abdominal pain. Cyclists have a high incidence of upper GI symptoms (eg, regurgitation, heartburn, nausea, and vomiting) [3,5,12,14,19]. Nausea is the most frequently reported symptom in ultramarathon runners [9,20,21].


Exercise-related transient abdominal pain — Exercise-related transient abdominal pain (ETAP) (side-stitch, stitch, or sub-costal pain) is a frequent cause of mild abdominal pain in athletes.

Incidence — The incidence of ETAP ranges from 6 to 68 percent [3-5,12,13,22,23]. ETAP occurs most frequently during long-distance running but has also been associated with other sports [22]. The incidence is higher in younger individuals and following recent ingestion of food and hypertonic fluids.

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Literature review current through: Sep 2017. | This topic last updated: Jul 25, 2017.
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  1. Gil SM, Yazaki E, Evans DF. Aetiology of running-related gastrointestinal dysfunction. How far is the finishing line? Sports Med 1998; 26:365.
  2. ter Steege RW, Kolkman JJ. Review article: the pathophysiology and management of gastrointestinal symptoms during physical exercise, and the role of splanchnic blood flow. Aliment Pharmacol Ther 2012; 35:516.
  3. Riddoch C, Trinick T. Gastrointestinal disturbances in marathon runners. Br J Sports Med 1988; 22:71.
  4. Worobetz LJ, Gerrard DF. Gastrointestinal symptoms during exercise in Enduro athletes: prevalence and speculations on the aetiology. N Z Med J 1985; 98:644.
  5. Sullivan SN. Exercise-associated symptoms in triathletes. Phys Sportsmed 1987; 15:105.
  6. Peters HP, De Vries WR, Vanberge-Henegouwen GP, Akkermans LM. Potential benefits and hazards of physical activity and exercise on the gastrointestinal tract. Gut 2001; 48:435.
  7. Bi L, Triadafilopoulos G. Exercise and gastrointestinal function and disease: an evidence-based review of risks and benefits. Clin Gastroenterol Hepatol 2003; 1:345.
  8. van Nieuwenhoven MA, Brouns F, Brummer RJ. Gastrointestinal profile of symptomatic athletes at rest and during physical exercise. Eur J Appl Physiol 2004; 91:429.
  9. Stuempfle KJ, Hoffman MD. Gastrointestinal distress is common during a 161-km ultramarathon. J Sports Sci 2015; 33:1814.
  10. Wright H, Collins M, Villiers RD, Schwellnus MP. Are splanchnic hemodynamics related to the development of gastrointestinal symptoms in Ironman triathletes? A prospective cohort study. Clin J Sport Med 2011; 21:337.
  11. ter Steege RW, Van der Palen J, Kolkman JJ. Prevalence of gastrointestinal complaints in runners competing in a long-distance run: an internet-based observational study in 1281 subjects. Scand J Gastroenterol 2008; 43:1477.
  12. Keeffe EB, Lowe DK, Goss JR, Wayne R. Gastrointestinal symptoms of marathon runners. West J Med 1984; 141:481.
  13. Morton DP, Richards D, Callister R. Epidemlology of exercise-related transient abdominal pain at the Sydney City to Surf community run. J Sci Med Sport 2005; 8:152.
  14. Sullivan SN, Wong C, Heidenheim P. Does running cause gastrointestinal symptoms? A survey of 93 randomly selected runners compared with controls. N Z Med J 1994; 107:328.
  15. Rehrer NJ, Janssen GM, Brouns F, Saris WH. Fluid intake and gastrointestinal problems in runners competing in a 25-km race and a marathon. Int J Sports Med 1989; 10 Suppl 1:S22.
  16. Küster M, Renner B, Oppel P, et al. Consumption of analgesics before a marathon and the incidence of cardiovascular, gastrointestinal and renal problems: a cohort study. BMJ Open 2013; 3.
  17. Sullivan SN. The effect of running on the gastrointestinal tract. J Clin Gastroenterol 1984; 6:461.
  18. Halvorsen FA, Ritland S. Gastrointestinal problems related to endurance event training. Sports Med 1992; 14:157.
  19. Peters HP, Bos M, Seebregts L, et al. Gastrointestinal symptoms in long-distance runners, cyclists, and triathletes: prevalence, medication, and etiology. Am J Gastroenterol 1999; 94:1570.
  20. Hoffman MD, Fogard K. Factors related to successful completion of a 161-km ultramarathon. Int J Sports Physiol Perform 2011; 6:25.
  21. Glace B, Murphy C, McHugh M. Food and fluid intake and disturbances in gastrointestinal and mental function during an ultramarathon. Int J Sport Nutr Exerc Metab 2002; 12:414.
  22. Morton DP, Callister R. Characteristics and etiology of exercise-related transient abdominal pain. Med Sci Sports Exerc 2000; 32:432.
  23. Sullivan SN. The gastrointestinal symptoms of running. N Engl J Med 1981; 304:915.
  24. Capps RB. Causes of the so-called side ache in normal persons. Arch Intern Med 1941; 68:94.
  25. SINCLAIR JD. Stitch: the side pain of athletes. N Z Med J 1951; 50:607.
  26. Morton DP. Exercise related transient abdominal pain. Br J Sports Med 2003; 37:287.
  27. Morton DP, Aragón-Vargas LF, Callister R. Effect of ingested fluid composition on exercise-related transient abdominal pain. Int J Sport Nutr Exerc Metab 2004; 14:197.
  28. Plunkett BT, Hopkins WG. Investigation of the side pain "stitch" induced by running after fluid ingestion. Med Sci Sports Exerc 1999; 31:1169.
  29. Beaumont AC, Teare JP. Subtotal colectomy following marathon running in a female patient. J R Soc Med 1991; 84:439.
  30. Kam LW, Pease WE, Thompson PD. Exercise-related mesenteric infarction. Am J Gastroenterol 1994; 89:1899.
  31. Kyriakos R, Siewert B, Kato E, et al. CT findings in runner's colitis. Abdom Imaging 2006; 31:54.
  32. Lucas W, Schroy PC 3rd. Reversible ischemic colitis in a high endurance athlete. Am J Gastroenterol 1998; 93:2231.
  33. Moses FM. Exercise-associated intestinal ischemia. Curr Sports Med Rep 2005; 4:91.
  34. Moses FM, Brewer TG, Peura DA. Running-associated proximal hemorrhagic colitis. Ann Intern Med 1988; 108:385.
  35. Clausen JP. Effect of physical training on cardiovascular adjustments to exercise in man. Physiol Rev 1977; 57:779.
  36. Rowell LB. Human cardiovascular adjustments to exercise and thermal stress. Physiol Rev 1974; 54:75.
  37. ter Steege RW, Geelkerken RH, Huisman AB, Kolkman JJ. Abdominal symptoms during physical exercise and the role of gastrointestinal ischaemia: a study in 12 symptomatic athletes. Br J Sports Med 2012; 46:931.
  38. van Wijck K, Lenaerts K, van Loon LJ, et al. Exercise-induced splanchnic hypoperfusion results in gut dysfunction in healthy men. PLoS One 2011; 6:e22366.
  39. Sanchez LD, Tracy JA, Berkoff D, Pedrosa I. Ischemic colitis in marathon runners: a case-based review. J Emerg Med 2006; 30:321.
  40. Ravi N, Stuart RC, Byrne PJ, Reynolds JV. Effect of physical exercise on esophageal motility in patients with esophageal disease. Dis Esophagus 2005; 18:374.
  41. Collings KL, Pierce Pratt F, Rodriguez-Stanley S, et al. Esophageal reflux in conditioned runners, cyclists, and weightlifters. Med Sci Sports Exerc 2003; 35:730.
  42. Yazaki E, Shawdon A, Beasley I, Evans DF. The effect of different types of exercise on gastro-oesophageal reflux. Aust J Sci Med Sport 1996; 28:93.
  43. Clark CS, Kraus BB, Sinclair J, Castell DO. Gastroesophageal reflux induced by exercise in healthy volunteers. JAMA 1989; 261:3599.
  44. Pandolfino JE, Bianchi LK, Lee TJ, et al. Esophagogastric junction morphology predicts susceptibility to exercise-induced reflux. Am J Gastroenterol 2004; 99:1430.
  45. Soffer EE, Merchant RK, Duethman G, et al. Effect of graded exercise on esophageal motility and gastroesophageal reflux in trained athletes. Dig Dis Sci 1993; 38:220.
  46. Soffer EE, Wilson J, Duethman G, et al. Effect of graded exercise on esophageal motility and gastroesophageal reflux in nontrained subjects. Dig Dis Sci 1994; 39:193.
  47. Parmelee-Peters K, Moeller JL. Gastroesophageal reflux in athletes. Curr Sports Med Rep 2004; 3:107.
  48. Otte JA, Oostveen E, Geelkerken RH, et al. Exercise induces gastric ischemia in healthy volunteers: a tonometry study. J Appl Physiol (1985) 2001; 91:866.
  49. Peters HP, Wiersma JW, Koerselman J, et al. The effect of a sports drink on gastroesophageal reflux during a run-bike-run test. Int J Sports Med 2000; 21:65.
  50. Peters HP, De Kort AF, Van Krevelen H, et al. The effect of omeprazole on gastro-oesophageal reflux and symptoms during strenuous exercise. Aliment Pharmacol Ther 1999; 13:1015.
  51. Murray R. The effects of consuming carbohydrate-electrolyte beverages on gastric emptying and fluid absorption during and following exercise. Sports Med 1987; 4:322.
  52. Moses FM. The effect of exercise on the gastrointestinal tract. Sports Med 1990; 9:159.
  53. Oktedalen O, Nesland A, Opstad PK, Berstad A. The influence of prolonged physical stress on gastric juice components in healthy man. Scand J Gastroenterol 1988; 23:1132.
  54. Stuempfle KJ, Valentino T, Hew-Butler T, et al. Nausea is associated with endotoxemia during a 161-km ultramarathon. J Sports Sci 2016; 34:1662.
  55. Sessions J, Bourbeau K, Rosinski M, et al. Carbohydrate gel ingestion during running in the heat on markers of gastrointestinal distress. Eur J Sport Sci 2016; 16:1064.
  56. Butcher JD. Runner's diarrhea and other intestinal problems of athletes. Am Fam Physician 1993; 48:623.
  57. Guillochon M, Rowlands DS. Solid, Gel, and Liquid Carbohydrate Format Effects on Gut Comfort and Performance. Int J Sport Nutr Exerc Metab 2017; 27:247.
  58. Sareban M, Zügel D, Koehler K, et al. Carbohydrate Intake in Form of Gel Is Associated With Increased Gastrointestinal Distress but Not With Performance Differences Compared With Liquid Carbohydrate Ingestion During Simulated Long-Distance Triathlon. Int J Sport Nutr Exerc Metab 2016; 26:114.
  59. Demers LM, Harrison TS, Halbert DR, Santen RJ. Effect of prolonged exercise on plasma prostaglandin levels. Prostaglandins Med 1981; 6:413.
  60. Fahrenkrug J, Haglund U, Jodal M, et al. Nervous release of vasoactive intestinal polypeptide in the gastrointestinal tract of cats: possible physiological implications. J Physiol 1978; 284:291.
  61. Oektedalen O, Flaten O, Opstad PK, Myren J. hPP and gastrin response to a liquid meal and oral glucose during prolonged severe exercise, caloric deficit, and sleep deprivation. Scand J Gastroenterol 1982; 17:619.
  62. Pals KL, Chang RT, Ryan AJ, Gisolfi CV. Effect of running intensity on intestinal permeability. J Appl Physiol (1985) 1997; 82:571.
  63. Payne DL, Welsh JD, Claypool PL. Breath hydrogen (H2) response to carbohydrate malabsorption after exercise. J Lab Clin Med 1983; 102:147.
  64. Lambert GP, Boylan M, Laventure JP, et al. Effect of aspirin and ibuprofen on GI permeability during exercise. Int J Sports Med 2007; 28:722.
  65. Van Wijck K, Lenaerts K, Van Bijnen AA, et al. Aggravation of exercise-induced intestinal injury by Ibuprofen in athletes. Med Sci Sports Exerc 2012; 44:2257.
  66. Bounous G, McArdle AH. Marathon runners: the intestinal handicap. Med Hypotheses 1990; 33:261.
  67. Casey E, Mistry DJ, MacKnight JM. Training room management of medical conditions: sports gastroenterology. Clin Sports Med 2005; 24:525.
  68. Six C, Aboukais S, Giron S, et al. Outbreak of diarrhoeal illness in participants in an obstacle adventure race, Alpes-Maritimes, France, June 2015. Euro Surveill 2016; 21.
  69. Hall V, Taye A, Walsh B, et al. A large outbreak of gastrointestinal illness at an open-water swimming event in the River Thames, London. Epidemiol Infect 2017; 145:1246.
  70. Kilgore PE, Belay ED, Hamlin DM, et al. A university outbreak of gastroenteritis due to a small round-structured virus. Application of molecular diagnostics to identify the etiologic agent and patterns of transmission. J Infect Dis 1996; 173:787.
  71. Stewart JG, Ahlquist DA, McGill DB, et al. Gastrointestinal blood loss and anemia in runners. Ann Intern Med 1984; 100:843.
  72. Halvorsen FA, Lyng J, Ritland S. Gastrointestinal bleeding in marathon runners. Scand J Gastroenterol 1986; 21:493.
  73. McCabe ME 3rd, Peura DA, Kadakia SC, et al. Gastrointestinal blood loss associated with running a marathon. Dig Dis Sci 1986; 31:1229.
  74. McMahon LF Jr, Ryan MJ, Larson D, Fisher RL. Occult gastrointestinal blood loss in marathon runners. Ann Intern Med 1984; 100:846.
  75. Robertson JD, Maughan RJ, Davidson RJ. Faecal blood loss in response to exercise. Br Med J (Clin Res Ed) 1987; 295:303.
  76. Schwartz AE, Vanagunas A, Kamel PL. Endoscopy to evaluate gastrointestinal bleeding in marathon runners. Ann Intern Med 1990; 113:632.
  77. Baska RS, Moses FM, Graeber G, Kearney G. Gastrointestinal bleeding during an ultramarathon. Dig Dis Sci 1990; 35:276.
  78. Fogoros RN. 'Runner's trots'. Gastrointestinal disturbances in runners. JAMA 1980; 243:1743.
  79. Papaioannides D, Giotis C, Karagiannis N, Voudouris C. Acute upper gastrointestinal hemorrhage in long-distance runners. Ann Intern Med 1984; 101:719.
  80. Rubin RB, Saltzman JR, Zawacki JK. Bicycle racing, Raynaud's phenomenon, and gastrointestinal bleeding. Am J Gastroenterol 1994; 89:291.
  81. Heer M, Repond F, Hany A, et al. Acute ischaemic colitis in a female long distance runner. Gut 1987; 28:896.
  82. Brotherhood J, Brozović B, Pugh LG. Haematological status of middle- and long-distance runners. Clin Sci Mol Med 1975; 48:139.
  83. Dufaux B, Hoederath A, Streitberger I, et al. Serum ferritin, transferrin, haptoglobin, and iron in middle- and long-distance runners, elite rowers, and professional racing cyclists. Int J Sports Med 1981; 2:43.
  84. Hunding A, Jordal R, Paulev PE. Runner's anemia and iron deficiency. Acta Med Scand 1981; 209:315.
  85. Martin RP, Haskell WL, Wood PD. Blood chemistry and lipid profiles of elite distance runners. Ann N Y Acad Sci 1977; 301:346.
  86. Stewart GA, Steel JE, Toyne AH, Stewart MJ. Observations on the haematology and the iron and protein intake of Australian olympic athletes. Med J Aust 1972; 2:1339.
  87. Peeling P, Dawson B, Goodman C, et al. Athletic induced iron deficiency: new insights into the role of inflammation, cytokines and hormones. Eur J Appl Physiol 2008; 103:381.
  88. Mercer KW, Densmore JJ. Hematologic disorders in the athlete. Clin Sports Med 2005; 24:599.
  89. Balaban EP, Cox JV, Snell P, et al. The frequency of anemia and iron deficiency in the runner. Med Sci Sports Exerc 1989; 21:643.
  90. Balaban EP, Snell P, Stray-Gundersen J, Frenkel EP. The effect of running on serum and red cell ferritin. A longitudinal comparison. Int J Sports Med 1995; 16:278.
  91. Di Santolo M, Stel G, Banfi G, et al. Anemia and iron status in young fertile non-professional female athletes. Eur J Appl Physiol 2008; 102:703.
  92. Fallon KE. Screening for haematological and iron-related abnormalities in elite athletes-analysis of 576 cases. J Sci Med Sport 2008; 11:329.
  93. Moses FM, Baska RS, Peura DA, Deuster PA. Effect of cimetidine on marathon-associated gastrointestinal symptoms and bleeding. Dig Dis Sci 1991; 36:1390.
  94. Thalmann M, Sodeck GH, Kavouras S, et al. Proton pump inhibition prevents gastrointestinal bleeding in ultramarathon runners: a randomised, double blinded, placebo controlled study. Br J Sports Med 2006; 40:359.