Int J Colorectal Dis (2012) 27:207–214 In 1999, Wasvary et al. published another modification, which since then has been widely adopted (see Table 2) [6]. This modification broadened the original Hinchey classifi- cation by not only addressing perforated disease, but also including mild clinical disease (stage 0). Additionally, a difference was made between confined pericolic inflamma- tion or phlegmon (stage Ia) and a confined pericolic abscess (stage Ib). Also in 1999, Köhler et al. published a consensus statement drawn up by the European Association of Endoscopic Surgeons entailing a clinical classification that differentiated symptomatic uncomplicated disease, recur- rent symptomatic disease, and complicated disease (see Table 3) [7]. In German literature since 1998, the Hansen/Stock classification has been mainly used. This is also a clinical classification accounting for asymptomatic diverticulosis as well as complicated diverticulitis in different stages, depending on the severity of the complications (see Table 4) [8]. These aspects make it probably the most useful classification in clinical practice; however, it has rarely been adopted in international literature. Another German classification published in 1995 by Siewert et al. followed a similar delineation for complicated disease [9]. Each classification accentuates different aspects of diverticular disease, creating its own strength and limita- tion. Moreover, some of these classifications appear to be used at random in today’s literature, thereby hampering adequate interpretation and comparison. Despite this variety of classifications, still a few clinical manifestations comprised by “diverticular disease” seem to be lacking; for example recurrent diverticular bleeding and post-inflammatory stenosis. Table 2 Modified Hinchey classification by Wasvary et al. and CT findings by Kaiser et al. Modified Hinchey classification by Wasvary et al. [6] 0 Ia Ib II III IV Mild clinical diverticulitis Confined pericolic inflammation or phlegmon Pericolic or mesocolic abscess Pelvic, distant intraabdominal, or retroperitoneal abscess Generalized purulent peritonitis Generalized fecal peritonitis CT findings by Kaiser et al. [20] Diverticuli ± colonic wall thickening Colonic wall thickening with pericolic soft tissue changes Ia changes + pericolic or mesocolic abscess Ia changes + distant abscess (generally deep in the pelvis or interloop regions) Free gas associated with localized or generalized ascites and possible peritoneal wall thickening Same findings as III 209 Purulent and fecal peritonitis Small bowel obstruction due to post-inflammatory adhesions Table 3 Classification by Köhler et al. Classification by Köhler et al. [7] Symptomatic uncomplicated disease Recurrent symptomatic disease Complicated disease Hemorrhage Fistula Abscess Perforation Phlegmon Stricture Clinical presentation As stated above, Köhler et al. presented a classification for diverticular disease based on the clinical severity and presentation of the disease. Although subjective complaints are obviously difficult to grade, Köhler et al. considered crampy pain in the left lower quadrant, fever, and changes in relief pattern to be symptomatic. One must consider that a large number of patients with complaints of pain in the left lower quadrant, fever, and soiling are probably out of clinical sight, consulting only their general practitioner. Such complaints are considered to be self-limiting, some- times assisted by antibiotic therapy. Published data on clinical episodes of diverticulitis do not account for these subjective complaints, leading to an underestimation of the real scale of these mild manifestations of diverticular disease. Furthermore, limitations of the clinical diagnosis of diverticulitis have to be regarded [10]. Clinical episodes are characterized by focus on more objective signs, like raised infectious parameters in laboratory tests and typical findings on CT scan or colonoscopy [1]. Yet, this does not discount the initial subjective complaints. It is the combination of specific symptoms that still form the basis for a differential diagnosis and the indication for additional examinations. For instance, impaired passage of a stool is suggestive for a stenosis, in which a colonoscopy can Table 4 Hansen/Stock and Siewert classification Hansen/Stock classification [8] Siewert et al. [9] 0 I II III Diverticulosis Acute uncomplicated diverticulitis Acute complicated diverticulitis a Phlegmon, peridiverticulitis b Abscess, sealed perforation c Free perforation Chronic recurrent diverticulitis I II III Pericolic abscess or phlegmon Pelvic, intraabdominal, or retroperitoneal abscess Free perforation