Various causes and conditions make for propensities for ischemia (this list is specifically for that of the colon, or ischemic colitis) like: medications causing constipation or blood flow interference; dehydration; infection or stomach virus; recreational drug use; surgery on the aorta; diabetes; cardiopulmonary diseases; and recent marathon running or other very strenuous activity causing severe dehydration. Ischemic colitis affects the final section of the gastrointestinal tract responsible for absorbing nutrients and water from digested food and turning waste into pee or poop and contributes to: low blood pressure; blood clots; hernias; tumor formation; autoimmune diseases (especially blood-related) and (rarely) colon cancer. Abdominal pain or discomfort, reduced eating, issues absorbing nutrients, diarrhea, and low-grade fever are all symptoms(2).
Loss of consciousness can involve abnormal body positions resulting in ischemia to a portion of the body. Frostbite and overmuch application of cold temperatures involve ischemia. Abnormal g-forces as occur in flight force blood to the extremities and restrict blood flow(1). Processed foods, inflammatory foods, and foods one is allergic too all cause gastric distress and contribute to ischemic colitis. Many veggies and wild-caught salmon are examples of inflammation-lowering foods; the preceding and fruits and healthy fats are helpful for those with high blood pressure. Being proactive against ischemia also basically involves taking care of heart health(2).
Sources:
1. Wikipedia contributors. "Ischemia." Wikipedia, The Free Encyclopedia. Wikipedia, The Free Encyclopedia. 11 June 2020. Web. 15 June 2020. https://en.wikipedia.org/wiki/Ischemia.
2. Levy, Jillian. "Prevent Painful Ischemic Colitis & Improve Symptoms Naturally." Dr. Axe, Dr. Axe. 20 October 2017. Web. 15 June 2020. https://draxe.com/health/ischemic-colitis/.