Causes

The precise cause of diminished blood flow to the colon isn't always clear. But several factors can increase your risk of ischemic colitis:

• Buildup of fatty deposits on the walls of an artery (atherosclerosis)
• Low blood pressure (hypotension) associated with dehydration, heart failure, surgery, trauma or shock
• Bowel obstruction caused by a hernia, scar tissue or a tumor
• Surgery involving the heart or blood vessels, or the digestive or gynecological systems
• Other medical disorders that affect your blood, such as inflammation of the blood vessels (vasculitis), lupus or sickle cell anemia
• Cocaine or methamphetamine use
• Colon cancer (rare)

The role of medications

The use of certain medicines also can lead to ischemic colitis, though this is rare. These medications include:

• Some heart and migraine medications
• Hormone medications, such as estrogen
• Antibiotics
• Pseudoephedrine
• Opioids
• Certain medications for irritable bowel syndrome
• Chemotherapy medications