Necrotizing colitis (NC), also called colonic necrosis, is a serious health problem. It happens when part of your colon dies. This is often due to decreased blood flow to the colon, which can be caused by problems such as:

• Arterial or venous obstruction (blood clots) involving the intestines
• Nonocclusive mesenteric ischemia (NOMI), which is reduced blood flow without a blockage
• Heart attack
• Abnormal heart rhythm (arrhythmia)
• Blockage in the abdominal blood vessels
• Colon cancer

If you have NC, it usually means you need to have emergency surgery.

Your large intestine is part of your digestive (gastrointestinal or GI) tract. The GI tract goes from your mouth down to your rectal opening. The large intestine is made up of your colon and rectum. The colon receives food that's broken down in your small intestine. One of the colon's main jobs is to reabsorb water and electrolytes, such as salt. The colon leads to your rectum. This is where your stool is stored before bowel movements.

In NC, part of the tissue in your colon dies. This happens when the cells on the wall of your colon don't get enough blood and oxygen.

NC in adults is an uncommon condition. It only happens if a health problem with the colon leads to trouble with blood flow. Necrotizing colitis in newborns (also called necrotizing enterocolitis) is a different condition.

Colon cancer is one cause of NC. But NC isn't a common complication from colon cancer. Other health problems that can cause NC include:

• Deep vein thrombosis (DVT)
• Pulmonary embolism (PE)
• Strangulated hernia
• Heart attack
• Arrhythmia (abnormal heart rhythm)
• Hirschsprung disease
• Diverticulitis or other types of inflammation in the abdomen
• Volvulus (twisting of the bowel)
• Fecal impaction
• Malfunctioning colostomy

All of these issues can block your colon. This can decrease blood flow to your colon. If the blood flow slows down or stops, part of your colon dies. This is because it doesn't get enough oxygen. The low oxygen levels also cause bacteria to grow. These bacteria may make toxins that can destroy nearby tissue.

Having certain health issues may raise your risk of NC. These may include:

• Diabetes
• Atherosclerosis
• Ischemic heart disease
• Using illegal drugs (certain illegal drugs decrease blood flow to the bowel)
• Smoking
• Underlying blood disorder that puts you at risk of blood clots
• Cirrhosis

People with NC have stomach pain and tenderness. This may be severe. This often comes on fairly suddenly. Other symptoms might include:

• Bleeding from your rectum
• Severe abdominal pain
• Nausea or vomiting
• Stomach swelling (distension)
• Constipation or diarrhea
• Fever
• Weight loss or signs of severe dehydration
• Symptoms of shock and sepsis. These may include low blood pressure, fainting, not making as much urine as normal, and confusion.

Your doctor will ask about your health history. They will also ask you about your symptoms and health conditions. They will look for health issues that can lead to NC, such as colon cancer. Your doctor will also give you a full exam, focusing on your abdomen.

You will have more tests before your doctor can tell if you have NC. These tests may include:

• Blood tests to check your red blood cell count. These tests can also look for infection and inflammation.
• Tests to measure the amount of oxygen in your blood
• Abdominal ultrasound, X-ray, or CT scan to show details of your GI tract
• Colonoscopy to look at your colon from the inside

A CT scan may show blockage in the blood vessels or inflamed colon tissue (colitis) or dead colon tissue (necrosis). A colonoscopy may show a blockage, such as colon cancer, colitis, or necrosis. But NC often can't be diagnosed until you have surgery.

You will likely need emergency surgery to treat NC. Your surgeon will take out the damaged part of your colon. They will then surgically join the parts that are left, if it is safe to do so.

Before and after the surgery, you may need supportive care. This means that you may need to stay in the intensive care unit of the hospital. Your treatment may include:

• Breathing support with a breathing machine (ventilator)
• I.V. (intravenous) fluids. This will treat shock.
• Blood transfusion. This is to help with blood loss during surgery.
• Antibiotics. These medicines will treat and prevent infections.

Your care plan will depend on your condition before and after surgery. You may also need treatment for the cause of your NC, such as colon cancer.

Many people fully recover after NC. Others may have long-term complications. This condition can even cause death. This is more likely if you don't seek treatment right away.

NC can lead to sepsis and shock. This can harm your organs. This might cause temporary or permanent damage, such as kidney failure. It can even cause severe shock. This may lead to death. Your health care team will work hard to prevent this.

Complications sometimes happen from surgery. For instance, you may have heavy bleeding or infection in another part of your body.

You may be able to reduce your chance of getting NC by following a healthy lifestyle. A healthy lifestyle includes:

• Eating a nutritious diet
• Keeping a healthy weight through diet and regular exercise
• Not smoking
• Limiting alcohol

Have colonoscopies as often as your doctor suggests. This may reduce your chance of getting colon cancer.

See your doctor right away if you have signs of NC. These include severe stomach pain.

• NC is a serious health problem. It happens when part of your colon dies.
• NC happens when there is a blockage in the blood vessels to your colon. This reduces blood flow to the tissue. This causes part of your colon to die.
• Severe stomach pain is often a symptom of NC.
• NC often needs emergency surgery. Your surgeon will take out the damaged part of your colon. NC often cannot be diagnosed until you have surgery.
• Many people fully recover after NC. Others may have long-term complications. This condition can sometimes cause death.

Tips to help you get the most from a visit to your doctor:

• Know the reason for your visit and what you want to happen.
• Before your visit, write down questions you want answered.
• At the visit, write down the name of a new diagnosis and any new medicines, treatments, or tests. Also write down any new instructions your doctor gives you.
• Know why a new medicine or treatment is prescribed and how it will help you. Also know what the side effects are.
• Ask if your condition can be treated in other ways.
• Know why a test or procedure is recommended and what the results could mean.
• Know what to expect if you do not take the medicine or have the test or procedure.
• If you have a follow-up appointment, write down the date, time, and purpose for that visit.
• Know how you can contact your doctor if you have questions, especially after office hours and on weekends and holidays.