The disease should be thought of when mucus diarrhea without red blood cells suddenly appears during or shortly after discontinuation of antibiotics, especially after the application of lincomycin or clindamycin; or when the condition worsens instead after abdominal surgery and diarrhea develops. The diagnosis can be quickly obtained by sigmoidoscopy, seeing pseudomembranes and positive cytotoxic assay in the feces.
I. Laboratory tests
Peripheral blood leukocytosis, mostly above 10,000-20,000/mm3, or even up to 40,000/mm3 or higher, with neutrophilia as the main cause. There is no specific change in fecal routine examination, only leukocytes, and blood in the flesh is rare. There is hypoalbuminemia, electrolyte imbalance or acid-base imbalance. Stool bacterial culture under special conditions reveals the growth of Clostridium difficile in most cases. The intra-fecal cytotoxic assay has a confirmatory value. The filtrate of the patient’s feces is diluted at different multiples and placed in tissue cultures to observe the cytotoxic effect, with diagnostic significance above 1:100. Clostridium difficile antitoxin neutralization test is often positive.
II. Endoscopy
When the disease is highly suspected, endoscopy should be performed promptly. The disease often involves the left hemicolectum, while the rectum may be free of lesions. Sigmoidoscopy is one of the important diagnostic tools. If the lesion is in the right hemicolectum, fiberoptic colonoscopy is required. If no typical lesions are found in the early stage, it is necessary to repeat the procedure. Endoscopic visual observation: In early stage or timely treatment, endoscopy may have no typical manifestation, and the intestinal mucosa may be normal or only mildly congested and edematous. In severe cases, enhanced mucosal fragility and obvious ulcer formation can be seen, and the mucosal surface is covered with yellow-white or yellow-green pseudomembrane.
X-ray examination
The abdominal plain film can show intestinal paralysis or mild or moderate intestinal dilatation. Barium enema examination can show thickening of the intestinal wall, significant edema, and disappearance of the colonic pouch. In some cases, gas between the intestinal wall can be seen, which is caused by partial intestinal wall necrosis and colon bacterial invasion; or ulcers or polyp-like lesions can be seen. The above-mentioned X-ray manifestations lack specificity, so the diagnostic value is small. Air barium contrast enema examination can improve the diagnostic value, but there is a risk of intestinal perforation, and should be used with caution.
The disease should be differentiated from ulcerative colitis, colonic Crohn’s disease, ischemic enteritis, and AIDS colitis.