Acute diverticulitis is an inflammation of one or more diverticulae that is clinically evident and visible endoscopically and occurs in nearly 4% of patients with diverticular disease, of which approximately 15% develop complications such as abscesses, perforations, fistulas or colonic obstruction, and 15%-30% may recur. Acute diverticulitis is the third most common gastrointestinal disorder among hospitalized patients in the United States, costing more than $2 billion annually, and is also a common condition in outpatient and emergency care. Recently, the American Gastroenterological Association Institute (AGA) published updated guidelines for the management of acute diverticulitis in the journal Gastroenterology. The guidelines were developed by the AGA’s Clinical Guidelines Committee and approved by the AGA Board of Directors.
The AGA has adopted the GRADE methodology (Clinical Recommendations Assessment, Development and Evaluation) for the development of clinical practice guidelines. According to GRADE terminology, the strength of the relevant recommendation is classified as strongly recommended, conditionally recommended or not recommended. A draft of the recommendation was then opened to the public by the AGA Board of Directors, edited with relevant comments and finally adopted.
Recommendations
Question 1: Should antimicrobials be routinely used in patients with acute simple diverticulitis?
The AGA recommends that for patients with acute simple diverticulitis, antimicrobials should be applied selectively rather than routinely. (Conditional recommendation, low quality evidence)
Antimicrobial drugs have long been the basis for the treatment of acute diverticulitis, and previous guidelines, textbooks, and expert opinion have recommended their routine use. In contrast, newer views suggest that the inflammatory factors of acute diverticulitis may be mostly infectious, and two recent randomized trials and two systematic reviews have not found a benefit from the application of antimicrobials and question the need for routine application of antimicrobials. Therefore, for patients hospitalized with CT-confirmed simple diverticulitis, this guideline recommends selective application of antimicrobials and following the principle of individualization.
It is important to emphasize that the current data quality is still low and this recommendation may change with further studies.
Question 2: Is colonoscopy required for acute simple diverticulitis confirmed by CT?
The AGA recommends that in patients with acute simple diverticulitis who have not had a recent high-quality colon examination, colonoscopy should be performed in appropriate patients to exclude colonic neoplasms (conditional recommendation, low quality evidence)
Observational studies of patients with imaging-confirmed acute simple diverticulitis have shown that subsequent colonoscopy may reveal a small number of patients with concomitant colorectal cancer (15 cases/1000) and high-risk adenomas (38 cases/1000). the absence of a mass on CT scan does not exclude the possibility of a colonic neoplasm. Although colonoscopy after an episode of acute diverticulitis could theoretically lead to an increased risk of recurrent diverticulitis or colonic perforation, no similar adverse events have been reported in the available literature.
Factors that may influence colonoscopy for acute simple diverticulitis include.
(1) timing and the completeness of previous colonoscopy;
(2) comorbidities ;
(3) persistent abdominal pain or diarrhea symptoms;
(4) patient preference. The risk of colonoscopy may be higher in patients with chronic diverticulitis, acute recurrent diverticulitis, or diverticulitis with comorbidities. The optimal timing of colonoscopy after an episode of acute diverticulitis has not been defined, but the severity and duration of disease should be considered. Colonoscopy is routinely recommended after 6-8 weeks of acute diverticulitis.
Question 3: Should patients with acute simple diverticulitis undergo selective colectomy after an episode?
AGA does not recommend elective colectomy in patients with acute simple diverticulitis and the decision to perform elective colectomy should be individualized (conditional recommendation, very low quality evidence)
About 20% of patients with acute simple diverticulitis will have recurrent diverticulitis within 5 years. Patients who are treated with medication and do not undergo colectomy are at a lower risk (<5%) of developing complications of diverticulitis or requiring urgent surgical treatment. Importantly, approximately 10% of patients with acute diverticulitis who undergo elective sigmoid resection face short-term surgical complications, including wound infection, anastomotic fistula, and cardiovascular/thrombotic events. patients over 65 years of age are at increased risk postoperatively.
Surgical treatment may reduce the risk of recurrence of diverticulitis, but the evidence for this remains limited and insufficient to support this hypothesis. Recent retrospective studies also challenge the existing guidelines that recommend elective colectomy for recurrent diverticulitis. In addition to patient age, individual factors, immunosuppression, surgical comorbidities, and patient preference should be taken into account for the surgical management of recurrent diverticulitis. Further confirmation is needed by comparing the results of randomized trials of surgical versus conservative treatment.
Question 4: Should a high-fiber diet or a conventional diet be used for those with previous acute diverticulitis?
The AGA recommends a high-fiber diet or intake of fiber supplements for those with a prior history of acute diverticulitis (conditional recommendation, very low quality evidence)
There are no studies showing that supplemental fiber intake reduces the risk of recurrence of acute diverticulitis. The role of fiber in relieving chronic abdominal pain in patients with diverticulitis is inconsistent, and the benefit is not significant in patients with recurrent diverticulitis. Although the benefit of fiber for acute simple diverticulitis is based on very low quality evidence, it can be determined that there is no significant risk with a high fiber diet or fiber supplement intake. The differences between dietary fiber and fiber supplements, and the optimal daily intake dose are unclear.
Question 5: Should the diet of those with prior acute diverticulitis avoid seeds, nuts, or popcorn?
The AGA does not recommend avoiding seeds, nuts or popcorn in the diet of individuals with acute diverticulitis (conditional recommendation, very low quality evidence)
There are no definitive data on the risk of ingestion of seeds, nuts, and popcorn and recurrence of diverticulitis, and the few studies that have been done have only conservatively estimated the relative risk. Until more convincing evidence emerges, it does not seem useful to advise patients to avoid these foods.
Question 6: Should aspirin be avoided in those with prior acute diverticulitis?
The AGA does not recommend avoiding aspirin in people with prior acute diverticulitis (conditional recommendation, low quality evidence)
Observational studies have shown that the risk of diverticulitis may be slightly increased with aspirin, and the assessment of diverticulitis with complications is not clear. Therefore, for patients with diverticulitis, the presence or absence of aspirin application is more relevant for non-diverticular disease. The moderate protective effect of aspirin application on overall mortality and on nonfatal myocardial infarction was partially offset by its increased risk of gastrointestinal bleeding.
The protective effect of aspirin in the secondary prevention of coronary artery disease is unquestionable and therefore far outweighs its risk of causing recurrence of diverticulitis in this subset of patients. The ability of aspirin to be used for primary prevention is inconclusive and individualized treatment should be followed.
Question 7: Should non-aspirin NASIDs be avoided in patients with prior acute diverticulitis disease?
The AGA recommends that non-aspirin NASIDs should be avoided in people with a history of acute diverticulitis (when circumstances permit) (conditional recommendation, very low quality evidence)
There is little information from studies on the use of non-aspirin NSAIDs and recurrence of diverticular disease. Results of observational studies suggest that use of this class of drugs can lead to an increased risk of diverticulitis and episodes of diverticulitis with complications.
Question 8: Can mesalazine be used in those with previous acute simple diverticulitis?
The AGA does not recommend the application of mesalazine after the occurrence of acute simple diverticulitis (strong recommendation, moderate quality evidence)
The efficacy of mesalazine for acute diverticulitis has been well studied by investigators in view of the inflammatory changes seen in the histology of acute diverticulitis. The current evidence suggests that mesalazine does not reduce the risk of recurrence or painful symptoms. This recommendation does not apply to recurrent diverticulosis or symptomatic simple diverticulosis.
Question 9: Can rifaximin be used in people with previous acute diverticulitis?
The AGA does not recommend rifaximin for patients with acute simple diverticulitis (conditional recommendation, very low quality evidence)
Rifaximin is a non-absorbable oral antibacterial drug. The recommendation to avoid routine application of rifaximin (very low quality evidence) does not apply to recurrent diverticulosis or symptomatic simple diverticulosis.
Question 10: Can probiotics be applied in those with previous acute diverticulitis?
The AGA does not recommend probiotics for patients with acute simple diverticulitis (conditional recommendation, very low quality evidence)
The AGA does not recommend routine use of probiotics in patients with acute simple diverticulitis due to the low quality of the evidence and the unclear impact of intestinal microecology on diverticulitis.
Question 11: Can people with prior acute diverticulitis engage in strenuous physical activity?
The AGA recommends that patients with diverticular disease consider heavy physical activity (conditional recommendation, very low quality evidence)
There is little research information on physical activity and recurrence of diverticular disease. One large observational study showed a modest reduction in the risk of diverticulitis in a population with vigorous physical activity.
Conclusion
The management of acute diverticulitis has evolved over the past decade to include a more rational application of antibiotics and surgery as well as initial and ongoing investigations of the efficacy of medications used to relieve symptoms and reduce recurrence. However, most of the current evidence is still of low quality and most of the recommendations are still limited. Priority areas for future research should include the following.
1. clarifying which patients in the acute diverticulitis patient population can apply and benefit from antimicrobial drugs;
2.Evaluate whether antimicrobial drugs, probiotics and dietary interventions can reduce symptoms and complications and/or decrease the recurrence rate of acute diverticulitis.
3.Identify risk factors for recurrence of diverticulitis to better develop medical interventions.
4. To identify the benefits, risks and timing of performing colonoscopy after an episode of acute diverticulitis.