# Investigation

Investigation

Radiology Plain radiographs can demonstrate a pneumoperitoneum. Spiral CT has excellent sensitivity and specificity for identify ing bowel wall thickening, abscess formation and extraluminal disease and has revolutionised the assessment of  complicated diverticular disease ( Figure 77.13 ). On identification of abscesses in stable patients, drainage, under interventional radiology guidance, ma y be carried out percutaneously , avoid ing the need for laparotomy/laparoscopy . Contrast studies and endoscopy are usually avoided for 6 weeks after an acute attack for fear of  causing perforation. They are used subsequently , howe ver, to exclude a coexisting carcinoma and assess the extent of  diverticular disease. Contrast examination or CT can demonstrate a fistula. Colonoscopy Endoscopic assessment may demonstrate the necks of  diver ticula within the bowel lumen ( Figure 77.14 ). A narrowed area of  diverticular disease may be impassable because of  the severity of  disease and there is a significant risk of  endoscopic perforation. Colonoscopy in these circumstances requires judgement and e xperience. Biopsies may be taken if  possible ally contrast enema is required. Excluding a carcinoma may not always be possible and may represent an indication for resection. 

Figure 77.13
Computed tomography scan demonstrating an abscess
associated with diverticulitis (arrow) (courtesy of Dr D Kasir, Hope
Hospital, Salford, UK).

Investigation

A supine abdominal radiograph is useful but not always diag - nostic ( Figure 77.17 ). CT is the mainstay of  diagnosis.