Large Intestine MCQs

Diarrhea is the most common manifestation caused by C. difficile. Stools are almost never grossly bloody and range from soft and unformed to watery or mucoid in consistency, with a characteristic odor. Clinical and laboratory findings include fever in 28% of cases, abdominal pain in 22%, and leukocytosis in 50%. When dynamic ileus (which is seen on x-ray in ~20% of cases) results in cessation of stool passage, the diagnosis of CDI is frequently overlooked. A clue to the presence of unsuspected CDI in these patients is unexplained leukocytosis , with ≥15,000 white blood cells (WBCs)/uL. Such patients are at high risk for complications of C. difficile infection, particularly toxic megacolon and sepsis . Reference : Harrison's principles of internal medicine, 21 st Ed, Ch:134 Pg: 1068

Clostridium difficile a Gram positive anaerobic bacterium is the cause of pseudomembranous colitis. Studies show that when C. difficile colonise the gut they release two potent toxins, toxin A and toxin B, which bind to certain receptors in the lining of the colon and ultimately cause diarrhoea and inflammation of the large intestine or colon (colitis). Commonly the disease is caused by broad spectrum antibiotics most commonly cephalosporins , broad spectrum penicillins and clindamycin . Less commonly, macrolides and quinolones have been reported to cause the disorder. Oral Vancomycin and Fidaxomycin are the agents used for mild infections. Metronidazole is reserved for fulminant cases. Reference : Harrison's Principles of Internal Medicine, 21 st ed, Ch: 138, Pg: 1069