Endoscopic significance of large bowel wall thickening on abdominal computed tomography scan (CT scan) of patients with no prior history of gastrointestinal disease

Background:In many abdominal cases computed tomography (CT) scan is used as a diagnostic modality. Bowel-wall thickening (BWT) is a widely documented finding in patients with no history of gastroenterologic disease on the examination of abdominal computed tomographies (CT). It is not clear what significance this nonspecific finding has. Aim: To study the significance of large bowel thickening in the CT scan by comparing it with colonoscopic diagnosis. Methods: All patients with age > 20 with CECT abdomen finding of thickened large bowel wall who had undergone colonoscopy within 30 days of CT scan were included in this study.  Colonoscopy was performed by experts after standard bowel preparation in all. The findings were noticed and biopsy was taken whenever necessary.  Patients with known history of gastrointestinal disease such as colon cancer, IBD, Tuberculosis, infectious colitis, or diverticulitis and ascites were excluded. Results: 173 patients with colonic thickening in CECT were included in the study. 112 (64.73 %) patients had abnormal colonoscopy findings and 61 (35.26 %) with normal colonoscopy. 76 (43.07 %) were males and 97 (56.07 %) were females. Abdominal pain was the most common indication for CECT, 107 patients (61.84 %).  47 had bleeding per rectum (27.16 %).  Mean Haemoglobin was 10.8 g /dl and 76 (43.07 %) patients had Hb < 10 g/dl. Mean ESR was 31.4 mm in and mean WBC count was 9360 /mm3. Elevated CEA was noticed in 60 patients (34.68 %) and elevated CRP in 51 patients (28.90 %). Mean time period between CECT and colonoscopy was 14 days ± 6. Conclusion: Bowel wall thickening on computed tomography (CT) scan has high predictive value for abnormal colonoscopic findings which includes serious conditions like colorectal malignancy, inflammatory bowel disease and intestinal tuberculosis in patients without pre-existing gastrointestinal disease.  CECT findings like Focal wall thickening and Colonic wall thickening > 7 mm and laboratory parameter of haemoglobin < 10 g /dl predict positive findings during colonoscopy in patients with colonic thickening in CECT. Colonic wall thickness of > 7 mm in CECT has a sensitivity of 60.7% and specificity of 54.1% to predict abnormal colonoscopic findin