Bowel Wall Thickening on Emergency Room CT Scans - Is It Always IBD?

Introduction: Patients presenting to Emergency Room with abdominal pain frequently undergo urgent CT scans, often revealing bowel wall thickening (BWT). In the absence of guidelines, endoscopic evaluation is performed in most of them. The study aims to evaluate the significance of such BWT and assess predictors of significant pathology on endoscopic evaluation Methods: Medical Records of patients referred to Gastroenterology Service with BWT on Emergency Department CT scans between July 2015-July 2017 at Hamad General Hospital, Qatar were retrospectively analyzed. Correlation of endoscopic findings to clinical presentation, laboratory parameters and histopathology was studied. Exclusion Criteria: 1. Endoscopy done after 4 weeks of CT scan reporting of BWT. 2. Patients with known GI Pathology (IBD, malignancy). 3. Evidence of luminal obstruction, stricture or mass on CT scan. Results: 109 of 160 referred patients satisfied criteria for study inclusion. Endoscopic appearance was normal in 37/109(33.9%). Significant findings confirmed as chronic pathology were found in 41/109(37.6%) patients. Of these 21(19.1%) had IBD {13 Crohn's Disease (11.9%), 8 Ulcerative Colitis (7.3%)}, 9(8.3%) had Tuberculosis, 11(10.1%) had malignancy. Mucosal abnormalities but normal or acute inflammation on histopathology were observed in 31/109(28.4%) patients.(Table 1) Age or gender had no correlation with significant findings. Symptom duration was the strongest predictor of significant endoscopic findings (> 2 weeks 25/35, 71.4%; < 2weeks 16/74, 21.6%; P< 0.001). Blood diarrhea, fever and weight loss were also positively associated with having significant findings. Laboratory parameters: WBC, Hemoglobin, ESR, Albumin and CRP were not correlated with IBD. Calprotectin was done in 36/109 patients. Mean Calprotectin was significantly higher with IBD and TB (199.5±299.8 vs 809.8±540.8; P< 0.001). Four radiologically reported parameters - fat stranding, lymphadenopathy, vascular engorgement and pelvic free fluid were analyzed from CT reports. Of these only fat stranding was associated with IBD or TB (20/46, 44% vs 10/52, 19%; P=0.009). Conclusion: One Third of the patients in the study had significant pathology (IBD/TB/Malignancy). Two thirds of patients had a negative endoscopy or acute inflammatory findings on endoscopy. Prospective data may guide patient selection for endoscopic evaluation in patients with Bowel Wall Thickening on CT scans.595_A Figure 1. Diagnosis and Distribution595_B Figure 2. Diagnosis595_C Figure 3. Calprotectin has high sensitivity and specificity to detect abnormality