Magnitude of the Problem 1 2 3 Etiology 4 1 Figure 1 Endoscopic images of diverticuli. Colonoscopy can be rather difficult when several diverticula are encountered because of increased colonic tortuosity and lack of distensibility.  5 6 7 8 Clinical Presentation and Evaluation The clinical presentations of diverticular disease range from asymptomatic diverticulosis, diverticulosis with periodic spasmodic abdominal pain and bloating, diverticulosis with hemorrhage, and finally, diverticulitis. Although diverticula can occur in any portion of the colon, this review will only focus on sigmoid diverticulitis, by far, the most common site for this disease process. 1 1 Table 1 Clinical Symptoms of Diverticulitis Symptoms Frequency (%) Left lower quadrant pain 93–100 Leucocytosis 69–83 Fever 57–100 Nausea 10–30 Vomiting 15–25 Constipation 10–30 Diarrhea 5–15 Dysuria 5–20 Urinary frequency 6–25 2 9 Figure 2 a b  Classification 10 2 Table 2 10 Grade Clinical Description Symptoms I Symptomatic uncomplicated disease Fever, crampy abdominal pain, CT evidence of diverticulitis II Recurrent symptomatic disease Recurrence of above III Complicated disease Hemorrhage Abscess Phlegmon Perforation Purulent and fecal peritonitis Stricture Fistula Obstruction 11 3 Table 3 11 Stage Description I Pericolic or mesenteric abscess II Walled off pelvic abscess III Generalized purulent peritonitis IV Generalized fecal peritonitis 12 4 Table 4 12 Mild Diverticulitis Severe Diverticulitis Localized sigmoid wall thickening (<5 mm) Abscess Inflammation of pericolic fat Extraluminal air Extraluminal contrast Management of Complicated Diverticulitis Surgical intervention is rarely indicated in cases of acute diverticulitis because most of these cases will resolve with appropriate antibiotic management. Operations are reserved for cases of complicated diverticulitis, i.e., patients with perforation and peritonitis, abscess formation, fistula, or obstruction. Although this may seem clear-cut, decisions regarding if and when to operate patients with diverticulitis remain a topic of significant debate. 1 13 14 1 13 14 15 16 3 Figure 3 Gross specimen of the sigmoid colon that was resected from a patient who presented with freely perforated diverticulitis (Hinchey III). Proximal margin extends to the area where the diverticuli end, and the distal margin is at the rectum.  Mention should be made of the meticulous surgical technique that must be used in this situation. The splenic flexure of the colon may need to be mobilized to ensure a tension-free anastomosis. One should imagine the rectum collapsing back into the pelvis with the patient standing upright when deciding on whether the bowel ends are truly free of tension. The margins of resection must be clearly viable with regard to vascularity. Finally, it may be best to avoid the crossed staple lines inherent to the double-stapled technique. Either a double pursestring technique with a stapled end-to-end anastomosis or a standard handsewn anastomosis are preferred when operating in an inflamed milieu. Preventive Surgery 1 17 1 18 19 20 Thus, it appears that elective resection might have little impact on the incidence of patients requiring emergency procedures because most of these occur with the first attack of diverticulitis. Subsequent attacks of diverticulitis in the same patient seem to be akin to their previous ones, suggesting that specific patients are predisposed to a set pattern of diverticulitis, and once settled into this pattern they stay within it. The threat of the colostomy bag to a patient who has been successfully managed medically during two previous attacks may be unwarranted and misleading. 21 22 severe 23 24 Diverticulitis in Young Men 1 25 26 27 26 26 28 Based upon these studies, we believe that young patients should generally be treated using the same criteria as older patients, and that the there is no justification for the routine recommendation for surgery after a single attack of diverticulitis in young patients. Elective preemptive surgery should be reserved for those who had at least two episodes of severe diverticulitis, and this decision should be supported by CT scan documentation of prior complicated disease. Fistulas 29 30 31 32 33 31 Diverticulitis in the Immunocompromised Patient 34 35 35 1 34 36 Conclusion The management of patients with sigmoid diverticulitis is still evolving. We should continue to constantly reassess the surgical dogma regarding the appropriate treatment of this common disease entity. Clearly, a randomized controlled study comparing the Hartmann’s procedure to primary anastomosis in the setting of perforated diverticulitis would be worthwhile. It is becoming increasingly clear that mandatory operations may not be warranted in young patients or those with two episodes of diverticulitis. As in other areas of clinical surgery, we must tailor our treatment to the specific situation for each individual patient.