Purpose and methods: In order to investigate the characteristics of the exercise-related transient abdominal pain (ETAP) commonly referred to as "stitch," a questionnaire was administered to a total of 965 regular sporting participants involved in six sports.
Results: The percentage of respondents claiming to have experienced ETAP within the past year for the respective sports were: running (69%, N = 439), swimming (75%, N = 103), cycling (32%, N = 76), aerobics (52%, N = 126), basketball (47%, N = 121), and horse riding (62%, N = 100). ETAP appears to be most prevalent in activities that involve repetitive torso movement, either vertical translation or longitudinal rotation. ETAP appears to be a single condition, common in its manifestation to most sufferers, and was described by respondents as a well-localized pain (79%), mostly experienced in the right or left lumbar regions of the abdomen (78%). The sensation of ETAP may be related to the severity of pain with less intense ETAP being described as cramping, aching, or pulling, and greater severity ETAP as sharp or stabbing in nature. Fourteen percent of respondents indicated that they experience shoulder tip pain (STP), which being the diaphragmatic-referred site could suggest irritation of the diaphragm. Respondents claiming to have experienced ETAP were more likely to report STP (r = 0.14, P < 0.01).
Conclusions: The findings of the present study provide perspective on previously suggested etiologies of ETAP, which include diaphragmatic ischemia and stress on the visceral "ligaments," and form the basis for examining alternative etiologies such as cramp of the musculature and irritation of the parietal peritoneum.