How does bowel ischemia cause acidosis?

Answer 1

Mesenteric or small intestine ischemia is a medical condition in which inflammation and injury of the small intestine result from inadequate blood supply. Causes of the reduced blood flow can include changes in the systemic circulation (e.g. low blood pressure) or local factors such as constriction of blood vessels or a blood clot. It is more common in the elderly.

Three progressive phases of ischemic colitis have been described:

A) A hyperactive phase occurs first, in which the primary symptoms are severe abdominal pain and the passage of bloody stools. Many patients get better and do not progress beyond this phase.


B) A paralytic phase can follow if ischemia continues; in this phase, the abdominal pain becomes more widespread, the belly becomes more tender to the touch, and bowel motility decreases, resulting in abdominal bloating, no further bloody stools, and absent bowel sounds on exam.



C) Finally, and this is impt as it's relevant to your question. A shock phase can develop as fluids start to leak through the damaged colon lining. This can result in shock and METABOLIC ACIDOSIS with dehydration, low blood pressure, rapid heart rate, and confusion. Patients who progress to this phase are often critically ill and require intensive care.

Answer 2

An ischemic bowel is unable to process nutrients, due to lack of blood flow, therefore causing acidosis.