Gastrointestinal Issues in Athletes
Although abdominal trauma can be a source of distress for the gastrointestinal (GI) system, simple athletic participation also can be associated with a variety of GI complaints and disorders.
- − 30% to 70% of athletes experience some type of GI disturbance (1,2), particularly runners, cyclists, and weight lifters (1).
- − 30% to 65% of runners will note a GI complaint.
- − Pain complaints tend to be more common in younger athletes and in those participating in longer-duration activities (2).
- − −The more fit the athlete, the less severe the symptoms (3).
- − The severity of symptoms increases with the intensity of activity and with fluid restriction (i.e., dehydration) (1,3).
GI disturbances in athletes have been attributed to several physiologic changes that occur naturally with athletics.
- − Decreased splanchnic blood flow
- − Blood flow is diverted to more metabolically active areas (i.e., muscles, skin) (1–4). The effects of this diversion are worsened with dehydration (2).
- − Reperfusion injury can occur after exercise and may be associated with increased gut permeability (1,2). This permeability allows for endotoxins to stimulate cytokine release and negatively affect the lower GI system (3).
- − During physical activity, the abdominal organs are in constant motion (1,2,4) and are often compressed by the abdominal wall musculature (1,2) or affected by the athlete's position during activity (e.g., cyclists) (1).
- – Altered neuroendocrine function, including increased sympathetic tone and altered GI hormones (1–3), affects motility (2).
The evaluation of an athlete with GI concerns should start in the same manner as the general evaluation for anyone with an abdominal issue (2). It will be important to determine whether the athlete's GI symptoms are due to exercise or whether the exercise is uncovering an as yet undiagnosed GI process (3).
- – Determine the source of the complaint
- − Common upper GI complaints include epigastric pain, painful/trouble swallowing, heartburn, nausea, and vomiting (1,2,4). A full stomach often worsens upper GI symptoms (3).
- − Common lower GI complaints include cramps, blood in stool (4), diarrhea (2,3), urgency, and increased stool frequency (3).
- – Note an association with other factors
- − There may be a pattern of the pain occurring after the athlete consumes certain foods, medications, supplements, alcohol, or tobacco (1,4). Be sure to obtain a diet history that includes meal timing, hydration status, and fluid preference (2).
- − Certain systemic illnesses also can present with and/or worsen GI complaints (1,4).
- − A change in the athlete's training also may have initiated or worsened the athlete's concern (2).
- −Be sure to rule out serious illness that may present with a GI complaint, including cardiac disease (e.g., MI) (1–4), cancer (1,3), inflammatory diseases (1,3), and asthma (2).
- − As noted above, the evaluation should include a full abdominal examination (1).
- − Providers also should look for signs of systemic illness, including wasting, rashes, lymph node enlargement, joint problems, and slow reflexes (4).
- −If there is a concern for systemic illness, proceed with ancillary testing (4), including the following:
- − Laboratories: complete blood count, iron studies, liver function tests, electrolytes, Helicobacter pylori, stool studies (including hemoccult) (1,4), and erythrocyte sedimentation rate.
- − Other studies, depending on the nature of the concern, may be warranted, including an EKG and stress test (1).
- – In general, treatment of GI complaints in athletes includes the following (specific treatments for conditions included in Table below):
- − dietary changes (aim to coordinate with exercise activity) (1)
- – consider keeping a food diary and entertain the possibility for certain food elimination (3)
- – avoid caffeine (3)
- – maintain fluid hydration before, during, and after activity (1,3)
- – watch carbohydrate intake (no more than 10% glucose solution) (1)
- − advance training program gradually (3)
- − stool before activity (3)
- − H2 blocker or PPI (if above strategies unsuccessful) (1).
The author declares no conflict of interest and does not have any financial disclosures.
1. Waterman JJ, Kapur R. Upper gastrointestinal issues in athletes. Curr. Sports Med. Rep
. 2012; 11:99–104.
2. Viola TA. Evaluation of the athlete with exertional abdominal pain. Curr. Sports Med. Rep
. 2010; 9:106–10.
3. Simons SM, Kennedy RG. Gastrointestinal problems in runners. Curr. Sports Med. Rep
. 2004; 3:112–6.
Copyright © 2019 by the American College of Sports Medicine
4. Baker J, DeLuca J, Beutler A. Netter’s Sports Medicine
. In: 2nd edition. Philadelphia (PA): Elselvier; 2018. Chapter 30, Gastrointestinal Problems. pp. 211–5.e1.