2 followed by the ascending colon. Ischemic colitis is mainly reported in the area from the left side of the transverse colon to the descending colon corresponding to the region of overlapping marginal blood supply due to the anastomosis between the superior and inferior mesenteric arteries known as Griﬃth’s point [8]. During exercise the sympathetic nervous system is stim- ulated resulting in a blood ﬂow shunt from the splanchnic system towards the muscles [2, 4–6]. This is the primary cause of ischemic colitis in athletes. It takes a 75% reduction for up to 12 hours in the mesenteric blood ﬂow to induce microscopic changes in the healthy colon. Exercising at 70% of maximal oxygen consumption (VO2 max) causes a splan- chnic blood ﬂow reduction up to 60–70% and more intense exercise can reduce blood ﬂow up to 80% [5, 6, 9, 10]. Dehydration is another factor that can be worsened by catecholamine suppression of the thirst response center [6, 11]. Hyperosmolar sport drinks and gels create a trans- luminal shift of water into the colon, thus contributing to the diarrhea and dehydration [6]. The splenic ﬂexure and the rectosigmoid junction are the watershed areas in the colon that are more prone to ischemia due to their lack of suﬃcient blood supply [3]. Not only are endurance athletes at risk for ischemic colitis, but many are at increased risk from chronic nons- teroidal anti-inﬂammatory drugs (NSAID) use. NSAIDs are commonly used to enable the athlete to return to training or competition. One study reported that athletes competing in speed and power sports use more NSAIDS than the general population [11]. At the 2000 Summer Olympics in Sydney, 26% of athletes had used NSAIDs within three days prior to competition. Others studies reported 38% of athletes at the Sydney Olympics had used NSAIDs and 33% of athletes at the 1996 Summer Olympics in Atlanta. NSAID use was highest among softball players in Atlanta (60%) and gymnasts in Sydney (100%) [11–13]. With the increase in use of nonprescription medications among athletes, providers must be aware of the potential side eﬀects [14]. While 20% of athletes have reported side eﬀects while taking NSAIDs, 9% reported gastrointestinal symptoms such as stomach pain, heart burn, or diarrhea [11]. It is well documented that NSAID use can lead to gastritis and peptic ulcer disease in the normal population; however it is unclear if NSAID use causes gastrointestinal bleeding in endurance athletes [6, 15]. 3.2. Diagnosis and Management. Ischemic colitis in endur- ance runners is characterized by frequent, loose bowel move- ments during or immediately after a run. “Runner’s diar- rhea” is most common in long-distance or marathon run- ners. The cause of runner’s diarrhea is not clear. One theory is that extreme exercise directs blood ﬂow away from the intestines—contributing to diarrhea. Most laboratory tests are normal unless the ischemia is severe, resulting in leukocytosis. If that is the case, then there may be a leukocytosis, metabolic acidosis, or eleva- tions in lactate and lactate dehydrogenase [9]. Imaging per- formed to rule out other etiologies of abdominal pain reveal thumbprinting, air-ﬁlled loops, and mural thickening in 21% of plain abdominal X-rays. Barium enema is reported to be Case Reports in Gastrointestinal Medicine abnormal in 75% of patients but is replaced by endoscopy and computed tomography (CT) [9]. CT reveals abnormal- ities in up to 90% of patients with ischemic colitis [9]. Even though colonoscopy is the most sensitive method for diag- nosis, there are no endoscopic ﬁndings that are speciﬁc for ischemia and can often be diﬃcult to diﬀerentiate from inﬂammatory bowel disease [9]. Mesenteric angiography is only recommended when there is concern for acute arterial mesenteric infarction [10]. In mild-to-moderate cases of ischemic colitis supportive care with intravenous ﬂuids, bowel rest, and close moni- toring for fever and peritoneal signs is suﬃcient. In more moderate-to-severe cases empiric broad spectrum antibiotics can be considered to reduce the risk of bacterial translocation and sepsis. Although there is insuﬃcient data to support the use of antibiotics, it is generally accepted because of the diﬃculty in determining what cases progress to gangrenous colitis. Most patients will clinically improve within 24–48 hours, but 20% will require surgery for resection of necrotic bowel [9]. Evidence suggests that increased use of NSAIDs by endurance runners may be a contributory factor of ischemic colitis. Athletes presenting with abdominal pain and diarrhea should be assessed for these predisposing factors. Based on a clinical research study of 611 subjects, 86.1% of gastroin- testinal (colonic) mucosal lesions are likely related to NSAID use [16]. Future research should encompass the challenges of diagnosis and management of individual patient symptoms. In reviewing similar cases, physicians should consider dosage, formulation, and necessity of NSAID regimens [15, 16]. Discontinuation of NSAIDs in our case likely assisted in the “spontaneous resolution” of symptoms. The patient pre- sented had a full recovery, enabling her to return to run- ning three days later. She has since participated in other marathons without complications. References [1] F. Baillie, Association of international marathons and distance races, 2011, http://aimsworldrunning.org/about.htm. [2] D. C. Cohen, A. Winstanley, A. Engledow, A. C. Windsor, and J. R. Skipworth, “Marathon-induced ischemic colitis: why running is not always good for you,” The American Journal of Emergency Medicine, vol. 27, no. 2, pp. 255.e5–255.e7, 2009. [3] L. D. Sanchez, J. A. Tracy, D. Berkoﬀ, and I. Pedrosa, “Ischemic colitis in marathon runners: a case-based review,” Journal of Emergency Medicine, vol. 30, no. 3, pp. 321–326, 2006. [4] T. A. Viola, “Evaluation of the athlete with exertional abdom- inal pain,” Current Sports Medicine Reports, vol. 9, no. 2, pp. 106–110, 2010. [5] E. P. De Oliveira and R. C. Burini, “The impact of physical exercise on the gastrointestinal tract,” Current Opinion in Clinical Nutrition and Metabolic Care, vol. 12, no. 5, pp. 533– 538, 2009. [6] G. W. K. Ho, “Lower gastrointestinal distress in endurance athletes,” Current Sports Medicine Reports, vol. 8, no. 2, pp. 85– 91, 2009. [7] J. Sreenarasimhaiah, “Diagnosis and management of ischemic colitis,” Current Gastroenterology Reports, vol. 7, no. 5, pp. 421– 426, 2005.