Ischemic colitis (IC) is caused by brief episodes of compromised blood flow to the colon. It is usually self-limiting. The condition can affect any part of the colon, sometimes involving more than one segment in the same individual [1]. IC is responsible for over 50% of reported cases of gastrointestinal ischemia, making it the most frequently encountered ischemic condition of the gastrointestinal tract [2]. There are numerous risk factors for developing IC, ranging from preexisting medical conditions affecting the cardiovascular system to obstructive lesions in the abdomen, drug use, and surgery [3] [4].

IC is commonly seen in individuals in and beyond the sixth decade of life. Patients often have preexisting vascular diseases such as atherosclerosis. In rare cases, otherwise healthy individuals with no predisposing factors and young people may develop spontaneous IC [5].

Presentation varies considerably. Furthermore, most symptoms are non-specific, making the diagnosis challenging. The typical presentation includes sudden onset of abdominal pain or discomfort, bloody stool, diarrhea, as well as an urge to defecate. In right-sided IC, abdominal pain is more likely to be experienced than bleeding per rectum. Patients are often apyrexic. Peritonitis may be present if there is gangrene. This is associated with septic shock and metabolic derangement. The true prevalence of the condition is likely higher than what is recorded in the literature, as many cases are self-limiting. In addition, due to the vague nature of IC symptomatology, some cases are incorrectly diagnosed.

IC can either be gangrenous or non-gangrenous, and these two types can be distinguished clinically. The majority of cases are non-gangrenous [6]. A small proportion of cases, of the gangrenous type, progress to chronic IC [6] [7]. Patients who tend to develop chronic disease are those with a longer period of initial IC, prolonged leukocytosis, or advanced age [5]. Another complication of IC is fulminant pancolitis, reported in less than 1 in 100 cases [6].

• Plethora

  RISK FACTORS A plethora of conditions may predispose to IC: Mesenteric artery emboli, thrombosis, or trauma may lead to occlusive vascular disease and impaired colonic perfusion[ 5 ]. [wjgnet.com]

• Pseudotumor

  These findings parallel the “thumbprints” or “pseudotumors” found on barium studies[ 5 ]. The purple submucosal hemorrhages usually dissipate within 48 h or are followed by ulceration. [wjgnet.com]

• Unconsciousness

  In this case, a 34-year-old female with depression presented to an emergency department after a period of unconsciousness, with urinary and bowel incontinence, following exposure to car exhaust. Her carboxyhemoglobin level was 23%. [ncbi.nlm.nih.gov]

• Rectal Bleeding

  Clinical vigilance for ischemic colitis is recommended for patients receiving lubiprostone who are presenting with abdominal pain and rectal bleeding. [ncbi.nlm.nih.gov]

• Hyperactive Bowel Sounds

  Compared with the young group, the elderly group had a less frequent hyperactive bowel sounds, a higher baseline levels of C-reactive protein(CRP) and a longer average periods of hospitalization. [ncbi.nlm.nih.gov]

• Venous Insufficiency

  However, chronic venous insufficiency due to obstruction of macrovascular mesenteric vein rarely causes ischemia of the bowel. This report describes the first case of ischemic colitis caused by obstruction of the mesenteric and splenic veins. [ncbi.nlm.nih.gov]

• Hyperactivity

  Compared with the young group, the elderly group had a less frequent hyperactive bowel sounds, a higher baseline levels of C-reactive protein(CRP) and a longer average periods of hospitalization. [ncbi.nlm.nih.gov]

  Three progressive phases of ischemic colitis have been described: A hyperactive phase occurs first, in which the primary symptoms are severe abdominal pain and the passage of bloody stools. [en.wikipedia.org]

As the symptoms of ischemic colitis are ambiguous, further tests and imaging are necessary to reach the diagnosis. Laboratory tests include the following:

• Basic tests such as a complete blood count and liver function tests.
• Markers for ischemia. These include lactate dehydrogenase, serum amylase, and creatine kinase.
• Stool cultures for E. coli (O157:H7 strain), shigella, and salmonella. Viral and parasitic organisms may also be tested for.

The following imaging methods are used:

• Abdominal radiograph- X-ray signs that may be observed are ileus, free air in the abdomen, as well as a thumbprint pattern due to damage to the intestinal wall [8].
• Computerized tomography (CT)- Early IC may go undetected by CT scanning; however, the method is still useful as it excludes other pathologies as the cause of symptoms. Air in the abdomen, or in the hepatic portal vein, is indicative of tissue infarction [9]. Other visible signs are bowel wall thickening and stranding.
• Colonoscopy- This is now the imaging technique of choice in IC, as direct visualization of the colon is made possible. This method has largely replaced barium enemas. A biopsy may be taken, although its usefulness is limited. The colon mucosa may display erythema, bleeding, petechiae, or edema.
• Ultrasonography.

Angiography and magnetic resonance imaging are not routine. Peritonitic patients require immediate fluid resuscitation and surgical intervention.

• Pyuria

  XGPN clinically presents with abdominal mass, pain, weight loss, anemia and pyuria. [ncbi.nlm.nih.gov]

• T Wave Inversion

  The patient's electrocardiogram showed sinus tachycardia with T-wave inversions in leads I, aVL and V3-V6. The troponin I level peaked at 3.7 ng/ml. [ncbi.nlm.nih.gov]

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2. Greenwald DA, Brandt LJ. Colonic ischemia. J Clin Gastroenterol. 1998;27(2):122-128.
3. Steele SR. Ischemic colitis complicating major vascular surgery. Surg Clin North Am. 2007;87(5):1099-1114,ix.
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