Exercise-Induced Ischemic Colitis From Home-Based High-Intensity Interval Training (HIIT)

Abstract

The current case presents a male in his 40s without significant past medical, surgical, or family history. Hematochezia started immediately after one hour of high-intensity interval training (HIIT), which included free-weight exercises and a circuit training instructional video. Relevant investigations included negative stool cultures and flexible sigmoidoscopy showing ischemic colitis in the mid-sigmoid. Histology also supported ischemic etiology, leading to the diagnosis of exercise-induced ischemic colitis (EIIC). The patient made a full recovery following supportive treatment, including intravenous fluid. To our knowledge, this is the first reported case of ischemic colitis secondary to HIIT performed at home. The case reviews risk factors for EIIC and highlights the diagnosis as being possible outside the context of long-distance and endurance exercise.

Keywords: diarrhoea; high-intensity exercise; ischaemic colitis; ischemic colitis; lower gestrointestinal bleed.

Figure 1. Images obtained during flexible sigmoidoscopy

Confluent colitis is evident from generalized erythema and loss of vascular pattern. This is interspersed by an overlying fibrinous exudate (arrowheads), which starts in the mid-sigmoid.

Figure 2. Histology slides of the sigmoid colon

(A) Sigmoid colonic mucosa (H&E-stained section, original magnification ×100) showing withered crypts (circled) in contrast to the more normal crypts in the upper and lower aspects of the image. (B) Sigmoid colonic mucosa (H&E, original magnification ×200) showing acute hemorrhage in the lamina propria and focal acute inflammation with neutrophil polymorphs in the crypt epithelium (arrow).