Biopsies can be taken via endoscopy to provide more information. Visible light spectroscopy, performed using catheters placed through the 5 mm channel of the endoscope, is diagnostic (see Diagnosis). Treatment
Except in the most severe cases, ischemic colitis is treated with supportive care. IV fluids are given to treat dehydration, and the patient is placed on bowel rest (meaning nothing to eat or drink) until the symptoms resolve. If possible, cardiac function and oxygenation should be optimized to improve oxygen delivery to the ischemic bowel. A nasogastric tube may be inserted if an ileus is present.Antibiotics are sometimes given in moderate to severe cases; the data supporting this practice date to the 1950s, although there is more recent animal data suggesting that antibiotics may increase survival and prevent bacteria from crossing the damaged lining of the colon into the bloodstream. The use of prophylactic antibiotics in ischemic colitis has not been prospectively evaluated in humans, but many authorities recommend their use based on the animal data.Patients being treated supportively are carefully monitored. If they develop worsening symptoms and signs such as high white blood cell count, fever, worsened abdominal pain, or increased bleeding, then they may require surgical intervention; this usually consists of laparotomy and bowel resection. Prognosis
Most patients with ischemic colitis recover fully, although the prognosis depends on the severity of the ischemia.
It is also important to differentiate ischemic colitis, which often resolves on its own, from the more immediately life-threatening condition of acute mesenteric ischemia of the small bowel.There are devices which test the sufficiency of oxygen delivery to the colon. The first device approved by the U.S. FDA in 2004 uses visible light spectroscopy to analyze capillary oxygen levels. Use during Aortic Aneurysm repair detected when colon oxygen levels fell below sustainable levels, allowing real-time repair. In several studies, Specificity has been 90% or higher for acute colonic ischemia, and 83% for chronic mesenteric ischemia, with a sensitivity of 71%-92%. This device must be placed using endoscopy, however. Diagnostic tests
There is a recent optical test, but it requires endoscopy (see Diagnosis). There are no specific blood tests for ischemic colitis. The sensitivity of tests among 73 patients were:
The white blood cell count was more than 15,000/mm3 in 20 patients (27%)
The serum bicarbonate level was less than 24 mmol/L in 26 patients (36%)Plain X-rays are often normal or show non-specific findings. In a series of 73 patients, plain abdominal radiography (56%) showing colic distension in 53% or a pneumoperitoneum in 3%.CT scans are often used in the evaluation of abdominal pain and rectal bleeding, and may suggest the diagnosis of ischemic colitis, pick up complications, or suggest an alternate diagnosis.Endoscopic evaluation, via colonoscopy or flexible sigmoidoscopy, is the procedure of choice if the diagnosis remains unclear. Ischemic colitis has a distinctive endoscopic appearance; endoscopy can also facilitate alternate diagnoses such as infection or inflammatory bowel disease.