Diverticulitis Treatment & Management

Updated: Aug 06, 2019
  • Author: Elie M Ghoulam, MD, MS; Chief Editor: BS Anand, MD  more...
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Approach Considerations

The management of patients with diverticulitis depends on their presentation severity, presence of complications, and comorbid conditions. Therefore, there is no standard treatment in the medical management of diverticular disease, including diverticulitis. [4]

The initial approach involves determining whether the patient has complicated or uncomplicated disease. [2] Uncomplicated diverticulitis is defined as localized diverticular inflammation without complication, whereas complicated diverticulitis consists of inflammation associated with a complication such as abscess, fistula, obstruction, bleeding, or perforation. [30] Computed tomography (CT) imaging can confirm the diagnosis of diverticulitis and distinguish between both disease processes.

Uncomplicated diverticulitis can be managed medically and in an ambulatory setting, whereas complicated disease requires a more aggressive approach that can often require urgent or elective surgery, and treatments that are specific to the complication itself (eg, abscess drainage). [2] A gastroenterology consultation may be helpful, as can further assistance with surgical and interventional radiology consultations. The modified Hinchey classification is based on CT scan findings and is used to categorize diverticulitis as well as help to guide appropriate interventions. [3]

Emergency colectomy is performed when severe complications arise or when the patient's condition does not respond to medical treatment. Complications requiring surgical intervention include the following: purulent peritonitis, uncontrolled sepsis, fistula, and obstruction. In a retrospective study of over 3000 patients, about 20% of patients admitted for acute diverticulitis required emergency colectomy.

Elective resection of the involved bowel segment after three episodes of uncomplicated diverticulitis to prevent further attacks is generally recommended by consensus guidelines. In addition, earlier resection for younger patients with diverticulitis as well as for patients who are immunocompromised has been proposed. As most complicated diverticulitis occurs on the first presentation and data for elective resection have come from small retrospective studies, this recommendation remains controversial.

Successful percutaneous drainage of a diverticular abscess has not been associated with greater recurrence or more severe disease and does not necessitate elective colectomy.

Antibiotics are known to be the mainstay of therapy for most patients with acute diverticulitis, but recent studies have questioned their necessity, especially in mild, uncomplicated disease. [4, 31] It appears that antimicrobial use in acute uncomplicated diverticulitis increases patients' stay in the hospital without lowering the overall or individual complication rates. [32]

A 2012 Cochrane review showed no significant benefit of antibiotic therapy in the treatment of uncomplicated diverticulitis, however these data were based mostly on one well-done randomized controlled trial. [33] The 2015 American Gastroenterological Association (AGA) guidelines stated that clinicians must be selective in using antibiotics in patients in this subgroup of patients. [5]

Patients who have been successfully treated for acute diverticulitis should be reassessed in 6-8 weeks. Those who are symptom free at that time should undergo colonoscopy to rule out malignancy, if they have not had a recent, high-quality colonic examination. [5]


Medical Care

The treatment approach for diverticulitis can be broadly classified into either uncomplicated disease or complicated disease, and it takes into account a few other special considerations. [15] Acute uncomplicated diverticulitis is successfully treated in 70%-100% of patients with conservative management. [34, 35, 36] Patients who present to the emergency department with uncomplicated diverticulitis appear to be able to be safely discharged on oral antibiotics, provided computed tomography (CT) scan findings have been evaluated. [37] However, those whose CT scan findings reveal complicated disease should be admitted for inpatient management with surgical consultation. [37]

The American Gastroenterological Association (AGA) suggests selective, rather than routine, use of antibiotics in patients with acute uncomplicated diverticulitis. [5, 38] Some studies indicate that nonantibiotic management of acute uncomplicated diverticulitis is safe and feasible. [31, 39]

Acute diverticulitis tends to be more severe in very elderly people and in patients who are immunocompromised or who have debilitating comorbid conditions, such as diabetes and renal failure.

Outpatient treatment of diverticulitis

Patients with mild diverticulitis, typically with Modified Hinchey stage 0 and Ia disease, can be started on an outpatient treatment regimen. This consists of a clear liquid diet and 7-10 days of an oral (PO) broad-spectrum antimicrobial regimen that covers anaerobic microorganisms, such as Bacteroides fragilis and Peptostreptococcus and Clostridium organisms, as well as aerobic microorganisms, such as Escherichia coli and Klebsiella, Proteus, Streptococcus, and Enterobacter organisms. Single and multiple antibiotic regimens are equally effective as long as both groups of organisms are covered. [6, 7] According to the World Gastroenterology Organisation (WGO) 2007 practice guidelines for diverticular disease, such a regimen should result in improvement within 48-72 hours. [1]

Note the following:

  • A typical oral antibiotic regimen is a combination of ciprofloxacin (or trimethoprim-sulfamethoxazole) and metronidazole. Monotherapy with moxifloxacin or amoxicillin/clavulanic acid are appropriate for outpatient treatment of uncomplicated diverticulitis.

  • Instruct patients about being on a clear liquid diet only, and that they can slowly advance the diet as tolerated after clinical improvement, which usually occurs within 2-3 days.

Inpatient treatment of diverticulitis

Hospitalization is required in the presence of evidence of severe diverticulitis, such as systemic signs of infection or peritonitis. Patients who are unable to tolerate oral hydration, whose condition is refractory to outpatient therapy (ie, persistent or increasing fever, pain, or leukocytosis after 2-3 days), who are immunocompromised, or who have comorbidities may also require hospitalization. Patients' pain may be severe enough to require parenteral narcotic analgesia.

Consider the following:

  • Initiate bowel rest and intravenous (IV) fluid hydration. Start broad-spectrum IV antibiotic coverage until culture results, if obtained, are available.

  • Monotherapy with beta-lactamase-inhibiting antibiotics or carbapenems provides broad antibacterial coverage and is appropriate for patients who are moderately ill and require inpatient admission. Such antibiotics include piperacillin/tazobactam, ampicillin/sulbactam, ticarcillin/clavulanic acid, imipenem, or meropenem.

  • Multiple drug regimens are also appropriate options in the hospital setting and may consist of metronidazole and a third-generation cephalosporin or a fluoroquinolone. Such antibiotics include ceftriaxone, cefotaxime, ceftolozane/tazobactam, ciprofloxacin, or levofloxacin. Previously, gentamicin was recommended as part of a multidrug regimen; although this agent is still a reasonable choice, substitution with a third-generation cephalosporin or a fluoroquinolone has been advocated to avoid the risk of aminoglycoside nephrotoxicity.

  • For immunocompromised patients, imipenem or meropenem may be preferred over ertapenem for better enterococcal and pseudomonal coverage.

  • Pain management is important. Morphine is acceptable for analgesia and is preferred over meperidine owing to the adverse effects associated with meperidine. Although early recommendations for pain management favored meperidine based on a theoretical risk of affecting bowel tone and sphincters, randomized prospective studies comparing the narcotic options are not available. Use of nonsteroidal anti-inflammatory drugs and corticosteroids have been associated with a greater risk of colon perforation and should be avoided whenever possible. [5] The AGA suggests against routinely advising avoidance of aspirin in those with a history of acute diverticulitis. [5]

  • Within 2-3 days of hospitalization, the patient's fever, pain, and leukocytosis should begin to resolve. The patient can then begin a clear liquid diet and advance as tolerated. If the patient tolerates oral intake and is clinically stable, they can be discharged to complete a 7-10-day course of PO antibiotic therapy.

  • If fever and leukocytosis do not resolve after 2-3 days of treatment or if serial examinations reveal worsening clinical signs or new peritoneal findings, a repeat CT scan of the abdomen is advisable to rule out an abdominal abscess or other complications. The WGO guidelines state that a lack of improvement should prompt clinical suspicion and an investigation for a phlegmon or an abscess. [1]

  • If a patient has a peridiverticular abscess that measures more than 4 cm in diameter (Hinchey stage II disease), CT scan-guided percutaneous drainage is indicated. This usually leads to a prompt (< 72 hour) reduction in pain, fever, and leukocytosis. Percutaneous drainage is also beneficial in that it may allow for elective surgery rather than emergency surgery, and it increases the likelihood of a successful one-stage procedure.

  • For abscess cavities containing gross fecal material or in the presence of a perforation, early surgical intervention is required.

IV tigecycline is no longer recommended for patients with a severe penicillin allergy due to an increased mortality risk relative to other antimicrobials used to treat severe infections. [40] This higher all-cause mortality warranted a US Food and Drug Administration (FDA) Drug Safety Communication in September 2010, and the addition of a Black Box Warning to its prescribing information. [40] In September 2013, an additional warning was added to the Black Box Warning to indicate that the increased risk of death with IV tigecycline occurred both with FDA-approved uses and nonapproved uses. [41] Tigecycline is now reserved for use in situations when alternative treatments are not suitable. [41]

Dietary and activity considerations


In mild episodes of diverticulitis, a clear liquid diet is advised. Clinical improvement should occur within 2-3 days; the diet can then be advanced as tolerated. In episodes of moderate to severe acute diverticulitis, administer nothing by mouth (NPO).

Once the acute episode of diverticulitis has resolved, the patient may advance their diet as tolerated and then maintain a lifelong high-fiber diet. Colonoscopy or, alternatively, barium enema with flexible sigmoidoscopy should be obtained after resolution of an initial episode (typically 2-6 wk after recovery) to exclude other diagnoses, such as malignancy, [5, 29] ischemia, and inflammatory bowel disease.

An increasing number of studies have reported the efficacy of different regimens of anti-inflammatory agents, including mesalamine; nonabsorbable antibiotics such as rifaximin; and probiotics alone or in combination in the management of diverticulitis. [42, 43] The AGA does not recommend the use of mesalamine, and it suggests against the use of rifaximin or probiotics, following acute uncomplicated diverticulitis. [5]

In the first US double-blind, placebo-controlled trial of the anti-inflammatory agent mesalamine for diverticulitis, 117 patients randomly assigned within 7 days of documented acute diverticulitis to a once-daily regimen of either 2.4 g delayed-release mesalamine or placebo over 12 weeks, followed by a 9-month treatment-free period, demonstrated persistently lower global symptoms scores for 10 gastrointestinal symptoms on a 0-6 Likert scale in patients receiving mesalamine compared with the placebo group. [43] The rate of complete response was significantly higher with the use of mesalamine than placebo at 6 weeks and 52 weeks, whereas probiotics in combination with mesalamine did not provide additional efficacy. [43]

Studies imply a high-fiber diet will prevent progression of diverticulosis. However, after patients have become symptomatic, the benefit of fiber supplementation is less clear. Recommending patients to avoid seeds and nuts is less common, since it is currently thought that they may not play a significant role in the development of diverticulitis, as previously believed.

Long-term management probably includes a high-fiber, low-fat diet.


Normal activity is possible after resolution of the acute episode. Patients with diverticular disease should consider vigorous physical activity. [5]


Surgical Care

An estimated 15%-25% of patients who present with a first episode of acute diverticulitis have complicated disease that requires surgery. According to the World Gastroenterology Organisation (WGO) 2007 guidelines, 15%-30% of patients admitted for the management of diverticulitis will need surgery during their admission, with a surgical mortality of 18%. [1]

Classic surgical indications include some features characteristic of Hinchey stage III or IV disease, as follows:

  • Free-air perforation with fecal peritonitis

  • Suppurative peritonitis secondary to a ruptured abscess

  • Uncontrolled sepsis

  • Abdominal or pelvic abscess (unless computed tomography scan-guided aspiration is possible)

  • Fistula formation

  • Inability to rule out carcinoma

  • Intestinal obstruction

  • Failing medical therapy

  • Immunocompromised status

  • Extremes of age

Recurrent episodes of acute diverticulitis

Elective surgery was previously recommended in any patient who had two or more episodes of diverticulitis that were successfully treated medically; other data have since called this practice into question when the patient is otherwise healthy.

Perioperative considerations

Preoperative antibiotics should be administered to all patients. Single- and multiple-drug regimens, as discussed in Medical Care, are appropriate choices. However, for patients with more extensive contamination, a single-drug regimen (with either imipenem/cilastin or piperacillin/tazobactam) or a multiple-drug regimen (with ampicillin, gentamicin, and metronidazole) may be warranted for peritonitis. Bowel preparation is usually possible for nonemergent situations.

Emergent surgical approach

Guidelines from the 2006 American Society of Colon and Rectal Surgeons (ASCRS) recommend emergency surgery for patients with diffuse peritonitis and for those whose condition fails nonoperative management. Also, patients who are immunosuppressed or immunocompromised are at an increased risk of disease refractory to medical therapy or of bowel perforation, and they should be approached with a lower threshold for surgery. [44]

A two-stage surgical approach is generally the most common procedure performed for the emergency treatment of acute diverticulitis. Note the following:

  • The preferred surgical approach in patients with fecal peritonitis and in most cases of purulent peritonitis is the traditional Hartmann procedure. [45, 46] It involves resection of the diseased segment of bowel, an end-colostomy, and closure of the rectal stump. Typically, 3 months later, a second procedure may be performed in which the colostomy is reversed and the intestinal continuity is reestablished with the rectal stump; however, this second operation can be technically difficult and is not performed in many patients.

  • An alternative to the Hartmann procedure involves resection of the diseased colon, primary anastomosis (with or without intraoperative colonic lavage), and creation of a proximal diverting stoma, either via colostomy or ileostomy. The second procedure in this process would be to close the stoma. This approach is primarily used when there are relative contraindications to the primary anastomosis but no purulent or feculent peritonitis, and there is nonedematous bowel. Its advantage lies in avoiding the technically difficult second stage used in the Hartmann procedure.

  • There is no role for extensive and unnecessary dissections, which open up tissue planes to infection and increase blood loss.

  • In a study that examined data from patients who had undergone the Hartmann procedure for acute diverticulitis and then (after a median 7-month period) underwent reversal surgery, Fleming and Gillen investigated the rate of, and risk factors for, complications linked to the reversal procedure and found that of 18 of 76 patients (25%) who underwent reversal had postreversal complications. [46] Risk factors for reversal complications included being a current smoker, having a low preoperative albumin level, and allowing a prolonged period to elapse between the Hartmann and reversal procedures. The authors concluded that despite the reversal surgery's significant complication rate, offering the operation to appropriately selected patients is acceptable. They also suggested that preoperative identification of modifiable risk factors may benefit patients. [46]

Elective surgery

The decision to proceed with elective surgery, typically at least 6 weeks after recovery from acute diverticulitis, should be made on a case-by-case basis. [5] The 2015 American Gastroenterological Association (AGA) guidelines suggest against elective colonic resection in patients with an initial episode of acute uncomplicated diverticulitis. [5] As recommended by the 2007 World Gastroenterology Organisation (WGO) guidelines, this decision should include consideration of the age and medical condition of the patient, the frequency and severity of attacks, and the presence of any persistent symptoms after the acute episode. [5] Other appropriate indications for elective colectomy include an inability to exclude carcinoma, following an episode of complicated diverticulitis treated nonoperatively, or after percutaneous drainage of a diverticular abscess. [1]

Note the following:

  • Regarding attack frequency, after one attack of acute diverticulitis, about one third of patients will have a second attack. After a second episode, a further one third will have yet another attack. According to the 2007 WGO guidelines, a repeat episode requires immediate surgery if complications occur, such as free perforation, obstruction, abscess that is not resolved by percutaneous drainage, fistulas, and failure to respond to treatment. [1]

  • Regarding disease severity, most patients who present with complicated diverticulitis do so at the time of their first episode. Therefore, once a patient's initial presentation has been determined to be uncomplicated or complicated, the patient's future episodes are likely to follow a similar course.

  • A one-stage surgical approach with resection and primary anastomosis is often possible in elective settings because the disease is well localized and/or significantly resolved. The bowel must be well vascularized, nonedematous, tension free, and well prepared. The proximal margin should be an area of pliable colon without hypertrophy or inflammation. The distal margin should extend to the upper third of the rectum where the taenia coalesce. Not all of the diverticula-bearing colon needs to be removed, as diverticula proximal to the descending or sigmoid colon are unlikely to result in further symptoms.

  • Patients with Hinchey stage I or II disease can usually have preoperative bowel preparation.

Three-stage procedure

The classic three-stage surgical approach is rarely indicated at present because of its high associated morbidity and mortality. This procedure is considered only in critical situations in which resection cannot safely be performed. Consider the following:

  • In the three-stage approach, the initial operation is simply drainage of the diseased segment and creation of a proximal diversion colostomy, without resection.

  • The second operation is performed 2-8 weeks later to resect the diseased bowel and perform a primary anastomosis.

  • A third operation, performed 2-4 weeks after the second operation, closes the stoma.


Increasing experience with laparoscopic techniques for colon resection suggests that some of its advantages include less pain, a smaller scar, and shorter recovery time. [47] There is no change in early or late complications, and the cost and outcome are comparable to open procedures. The laparoscopic approach is best suited for patients in whom the episode of acute diverticulitis has resolved and in patients with Hinchey stage I or II disease.

Special considerations

Consider the following for some forms of complicated diverticulitis:

  • Diffuse peritonitis: An appropriate initial empiric antibiotic regimen must include either single-agent therapy with imipenem/cilastin or piperacillin/tazobactam or multidrug therapy with ampicillin, gentamicin, and metronidazole.

  • Differentiate obstruction from carcinoma. Even if biopsy results are negative, resection may be necessary to exclude carcinoma if there is enough suspicion based upon appearance alone.

  • Abscesses without peritonitis may be amenable to percutaneous drainage with an elective single-stage operation after the episode has resolved. Drainage is usually performed through the anterior abdominal wall, but it may be done transgluteally or through the rectum or the vagina, depending on the location of the abscess. Catheter drainage may be helpful in patients who cannot undergo surgery; the catheter should be left in place until the drainage is less than 10 mL in 24 hours. Obtain periodic catheter sinograms to monitor the resolution of the abscess cavity before the catheter is removed.

  • Fistulas generally do not close spontaneously, but they may be managed with an elective one-stage procedure in most cases. Also, in the absence of urinary tract obstruction, observation appears to be safe in patients with contraindications to surgery.

  • Patients who are immunosuppressed are at an increased risk for perforation. Surgery is necessary in almost all patients who are either already immunosuppressed or are about to start immunosuppressive therapy.

  • Elderly patients: Septic, hemodynamically unstable elderly patients with acute complicated diverticulitis should undergo surgical intervention as soon as possible, regardless of their Hinchey stage. [48] Fit and hemodynamically stable geriatric patients have surgical options similar to those of their younger counterparts; those who are frail but hemodynamically stable should undergo a Hartmann procedure.



A lifelong high-fiber diet for those with asymptomatic diverticular disease may reduce the incidence of diverticulitis and its complications. The 2015 American Gastroenterological Association (AGA) guidelines suggest a fiber-rich diet or fiber supplementation in individuals with a history of acute diverticulitis. [5] However, the guidelines are against routinely advising these patients to avoid the consumption of popcorn and nuts.

According to a large study in the United Kingdom, a high-fiber diet and a vegetarian diet were each significantly associated with a lower risk of diverticular disease-related hospital admission or death. [49]


Long-Term Monitoring

After recovering from acute diverticulitis, patients should have their colons examined to rule out malignancy. Current modalities include colonoscopy, barium enema, and computed tomography (CT) colonography (virtual colonoscopy).

Virtual colonoscopy may be helpful in evaluating diverticulitis in the elective setting. This procedure combines insufflation of the colon in conjunction with a CT scan to provide data that allow computer generation of a three-dimensional image. Although the technology is widely available in many centers, it is limited by the inability to sample suspicious lesions.

Biopsy of suspicious lesions or strictures can be performed during colonoscopy, which is advantageous.