Question Of The Day #95

This patient arrives to the Emergency department with bright red bloody stools and lower abdominal pain.  The exam shows fever, tachycardia, and left-sided abdominal tenderness.  The laboratory results provided show leukocytosis and anemia.  This patient likely has a lower GI bleed based on her signs and symptoms.  Please refer to the chart below for a list of causes of GI bleeding, GI bleeding signs and symptoms, and the initial Emergency Department treatment of GI bleeding. 

All choices provided are causes of lower GI bleeding and are possible in this patient.  However, that patient’s signs, symptoms, and risk profile make certain diagnoses less likely than others.  Diverticulosis (Choice A) is the most common cause of lower GI bleeding.  Diverticulosis often occurs in older patients and should not be associated with pain or fever, which support a diagnosis of an inflammatory or infectious etiology (i.e., diverticulitis, Shigellosis, ulcerative colitis, chron’s disease, etc.).  This patient is young and has fever and leukocytosis, making diverticulosis less likely.  Colon malignancy (Choice B) is also possible but is less likely given the patient’s young age, the presence of fever, and the acute onset of symptoms over 2 days.  Colon malignancy tends to cause slow GI bleeding over a longer period of time, rather than acutely over 2 days.  Ischemic colitis (Choice C), such as mesenteric ischemia, is less likely in a young patient without any cardiac risk factors or recent abdominal surgeries. 

Ulcerative colitis (Choice D) is the most likely diagnosis in this scenario.  Peak incidence for ulcerative colitis occurs in the second and third decades of life, and women are more likely than men to have this diagnosis.  Definitive diagnosis requires a biopsy and colonoscopy, but a CT scan of the abdomen and pelvis can show findings consistent with ulcerative colitis for a new diagnosis.  Treatment of an ulcerative colitis flare includes general supportive care, IV steroids, and IV antibiotics if there is concern for a concurrent infectious process.  Intestinal perforation and toxic megacolon also should be evaluated for with CT imaging.