• Welcome to Crohn's Forum, a support group for people with all forms of IBD. While this community is not a substitute for doctor's advice and we cannot treat or diagnose, we find being able to communicate with others who have IBD is invaluable as we navigate our struggles and celebrate our successes. We invite you to join us.

Blood in Stool, Other Factors Suggest Crohn's Disease Over Intestinal Tuberculosis

Blood in stool and sigmoid colon involvement are among the features that support a diagnosis of Crohn's disease over intestinal tuberculosis, say researchers in the January 19th online issue of the American Journal of Gastroenterology. Weight loss, by contrast, predicts intestinal tuberculosis.

The features of Crohn's disease and intestinal tuberculosis mimic each other to a large extent, the authors explain, making it challenging to differentiate between them in geographical regions where both are prevalent.

Dr. Govind K. Makharia and colleagues from All India Institute of Medical Sciences, New Delhi, analyzed the clinical, endoscopic, and histological features in 106 patients, 53 each with Crohn's disease and intestinal tuberculosis, in an effort to identify characteristics that differentiate the two conditions.

The mean patient age was older and the median duration of disease was longer with Crohn's disease than with intestinal tuberculosis, the authors report. However, on further analysis, neither was found to be a significant independent predictor of Crohn's disease.

On multivariate analysis, blood in stool (OR, 0.1), sigmoid colon involvement (OR, 0.07), and focally enhanced colitis (OR, 0.1) were all predictive of the disease not being intestinal tuberculosis, but Crohn's disease. By contrast, weight loss (OR, 9.8) was highly predictive of the disease being intestinal tuberculosis and not Crohn's.

When the investigators incorporated these features into a single score, 91% of patients could be correctly discriminated. At their selected cutoff score, the model was 83.0% sensitive, 79.2% specific, and 81.1% accurate in classifying the two diseases.

"Although there are similarities between Crohn's disease and intestinal tuberculosis, these two can be differentiated on the basis of a combination of clinical manifestations, endoscopic features, and histological features," the researchers conclude.

"These are single-center data and further validation studies are required," the authors caution. "If in doubt, a trial of anti-tuberculosis therapy is still recommended before commencing immunosuppressive therapy."

Am J Gastroenterol 2010.
Is the test for intestinal TB the same one you get before starting Humira/Remicade? I think it is called a Mantoux test.