208 system. A second analysis using manual cross reference search of the bibliographies of relevant articles located studies not found in the first search. The third strategy used the “related article” function in PubMed to select articles not found in above searches. All articles in English, German, and Dutch have been included. A total of nine classifications and modified classifications for diverticular disease were collected. Classifications A proper classification system can improve mutual com- munication between doctors of different specialties and support clinical decision making. This seems indispensible for the management of the wide spectrum of manifestations and many treatment modalities embraced by the term “diverticular disease”. Uniform classification in clear subgroups of diverticular disease could help the clinician in predicting outcomes and prognosis more accurately. In 1978, Hinchey et al. published their classification for acute diverticulitis [3]. The Hinchey classification has traditionally been used in international literature to distin- guish four stages of perforated disease (see Table 1). This most widely used classification was actually based on an earlier clinical division of acute diverticulitis published by Hughes et al. (see Fig. 1) [4]. Since the introduction of the computed tomography (CT scan) in the 1980s, this imaging modality has established itself as the primary diagnostic tool in the assessment of diverticular disease (see Fig. 2). The much more detailed information provided by CT scans led earlier to modifications of the original Hinchey classification. Subcategories could be defined by taking the radiological findings into account. Hence, in 1997, Sher et al. introduced the first modification for distinguishing between a pericolic abscesses (stage I), distant abscesses amendable for percutaneous drainage (stage IIa), and complex abscesses Table 1 Hinchey classification and modified Hinchey classification by Sher et al. Hinchey classification [3] Modified Hinchey classification by Sher et al. [5] I II III IV Pericolic abscess or phlegmon Pelvic, intraabdominal, or retroperitoneal abscess Generalized purulent peritonitis Generalized fecal peritonitis I IIa IIb III IV Pericolic abscess Distant abscess amendable to percutaneous drainage Complex abscess associated with fistula Generalized purulent peritonitis Fecal peritonitis Int J Colorectal Dis (2012) 27:207–214 Fig. 1 Hughes classification (Hughes et al. [4], reproduced with permission) associated with a possible fistula (stage IIb) [5]. This modification also implied the use of new treatment strategies, such as CT-guided percutaneous drainage of abscesses. Fig. 2 CT scan images resembling the four Hughes stages. I Pericolic phlegmon with small associated abscess. II Large intraabdominal abscess. III Small amounts of free air and fluid. IV Massive pneumoperitoneum and free fluid