What are the guideline sources, guidelines and references for Acute diverticulitis ?
Guideline sources The following summarized guidelines for the evaluation and management of acute diverticulitis are prepared by our editorial team based on guidelines from the American College of Radiology (ACR 2023; 2022), the Academy of Emergency Medicine and Care (AcEMC/SIFIPAC/SICUT/WSES/ACOI/SICG 2022), the German Society of General and Visceral Surgery (DGAV/DGVS 2022), the American College of Physicians (ACP 2022), the European Society of Coloproctology (ESCP 2020), the World Society of Emergency Surgery (WSES 2020), the American Society of Colon and Rectal Surgeons (ASCRS 2020; 2014), the Japanese Gastroenterological Association (JGA 2019), and the American Gastroenterological Association (AGA 2015). 1 2 3 4 5 6 7 8 9 10 11 12 13 13 14 15 Definition https://web.pathway.md/diseases/rec3Z5lhIppiQuZrO 1/13 6/23/23, 1:44 AM Acute diverticulitis Pathway Acute diverticulitis is a disease resulting from acute inflammation and/or micro-perforation of colonic diverticula. 12 Epidemiology The putative etiology of acute diverticulitis include alterations in colonic structure, colonic motility, microbiome, genetics, immune system, in addition to connective tissue disorders and environmental factors (obesity, smoking, non-steroidal anti-inflammatory drugs). 14 Pathophysiology The incidence of acute diverticulitis has increased in the past several decades and is estimated at 188 cases per 100,000 person-years in the United States. 13 Disease course Alterations in gut motility, intraluminal pressure, and the accumulation of inspissated fecal particles in diverticula leads to erosion of the diverticular wall, causing inflammation that can progress to perforation and diffuse peritonitis. The sequelae of diverticula covered by mesentery may cause phlegmons or abscesses, as well as fistulas. 15 Prognosis and risk of recurrence Acute diverticulitis has a recurrence rate of 13-23% in patients with uncomplicated disease, and around 40% in patients with complicated disease. 13 Guidelines 1. Screening and diagnosis Differential diagnosis: Include diverticulitis in the differential diagnosis of acute abdominal pain, even in younger patients (< 40 years of age). B Include diverticulitis in the differential diagnosis of acute abdominal pain, even if the localization of pain is right-sided or suprapubic. E 2. Diagnostic investigations Initial evaluation: As per DGVS 2022 guidelines, elicit medical history B and perform a physical examination in patients with suspected diverticulosis. B Show 3 more As per WSES 2020 guidelines: https://web.pathway.md/diseases/rec3Z5lhIppiQuZrO 2/13 6/23/23, 1:44 AM Acute diverticulitis Pathway Consider obtaining a complete assessment including clinical history, signs, laboratory inflammation markers, and radiological findings in patients with suspected acute left-sided colonic diverticulitis. C Do not rely solely on clinical examination for the diagnosis of patients with suspected acute left-sided colonic diverticulitis. D As per JGA 2019 guidelines, examine for complications such as abscess, perforation, and peritonitis at the initial assessment for colonic diverticulitis. B As per ASCRS 2014 guidelines, elicit problem-specific history, perform a physical examination, and obtain appropriate laboratory studies in the initial evaluation of patients with suspected acute diverticulitis. B Diagnostic imaging: As per ACR 2023 guidelines, obtain CT of the abdomen and pelvis with IV contrast for the initial imaging of LLQ pain, including suspected diverticulitis or complications of complications. B As per ACP 2022 guidelines, consider obtaining abdominal CT if there is diagnostic uncertainty in patients with suspected acute left-sided colonic diverticulitis. C As per ACR 2022 guidelines, obtain CT of the abdomen and pelvis with IV contrast for the initial imaging of RLQ pain. B As per DGVS 2022 guidelines, obtain cross-sectional imaging (ultrasound or CT) to confirm the diagnosis of diverticulitis. A Show 2 more As per ESCP 2020 guidelines, obtain imaging to confirm the diagnosis of acute diverticulitis if there is no proceeding diagnostic information. B Show 3 more As per WSES 2020 guidelines, consider obtaining an ultrasound (by an expert operator) in the initial evaluation of patients with suspected acute left-sided colonic diverticulitis. C Show 2 more As per JGA 2019 guidelines, obtain diagnostic imaging (CT scan of the abdomen and pelvis or abdominal ultrasound) in patients with suspected acute diverticulitis, in addition to physical examination and laboratory testing. B As per ASCRS 2014 guidelines: Obtain CT of the abdomen and pelvis as the most appropriate initial imaging modality for the assessment of patients with suspected acute diverticulitis. B Consider ultrasound and MRI as useful alternatives for the initial evaluation of patients with suspected acute diverticulitis when CT is not available or is contraindicated. B Poppy seed test: obtain a poppy seed test in patients with suspected sigmovesical fistula, if the fistula has not already been described morphologically (ultrasound, CT, MRI, colonoscopy). B 3. Diagnostic procedures https://web.pathway.md/diseases/rec3Z5lhIppiQuZrO 3/13 6/23/23, 1:44 AM Acute diverticulitis Pathway Colonoscopy: consider performing a colonoscopy (probably with a slightly increased risk of perforation) in certain situations (such as an uncharacteristic clinical picture or disease course) in patients with acute diverticulitis, provided covert perforation and abscesses have been ruled out. C Show 4 more 4. Medical management Setting of care: As per ACP 2022 guidelines, manage most patients with acute uncomplicated left-sided colonic diverticulitis in an outpatient setting. B As per ESCP 2020 guidelines, consider managing patients with uncomplicated diverticulitis in an outpatient setting in the absence of sepsis, significant comorbidity, immunosuppression and with an adequate social network tolerating oral intake. C As per WSES 2020 guidelines, consider managing patients with uncomplicated acute left-sided colonic diverticulitis and no comorbidities in an outpatient setting. Consider reevaluation within 7 days. Reevaluate earlier if the clinical condition deteriorates. C Indications for non-operative management: As per ESC 2020 guidelines, consider observing immunocompetent hemodynamically stable patients with diverticulitis even if there are radiological signs of extraluminal air. C As per WSES 2020 guidelines: View immunocompromised patients with acute left-sided colonic diverticulitis as patients at high risk for failure of standard, nonoperative treatment. B Consider a nonoperative treatment in selected patients with CT findings of distant free gas without diffuse intra-abdominal fluid, only if a close follow-up can be performed. C Antibiotic therapy: As per ACP 2022 guidelines, manage selected patients with acute uncomplicated left-sided colonic diverticulitis initially without antibiotics. B As per ASCRS 2020 guidelines: Treat selected patients with uncomplicated diverticulitis without antibiotics. A Consider antibiotic therapy for nonoperative treatment of patients with diverticulitis. B As per ESCP 2020 guidelines, do not routinely offer antibiotic therapy in patients with acute uncomplicated diverticulitis. Show 2 more As per WSES 2020 guidelines, do not offer antibiotic therapy for immunocompetent patients with uncomplicated diverticulitis without signs of systemic inflammation. D Show 5 more As per JGA 2019 guidelines, consider antibiotic therapy in patients with acute diverticulitis, acknowledging that antibiotics have been reported to be unnecessary for colonic diverticulitis https://web.pathway.md/diseases/rec3Z5lhIppiQuZrO 4/13 6/23/23, 1:44 AM Acute diverticulitis Pathway without abscess or perforation. C Show 2 more As per AGA 2015 guidelines, consider the use of antibiotics selectively, rather than routinely, in patients with acute uncomplicated diverticulitis. C As per ASCRS 2014 guidelines, administer oral or IV antibiotics and implement dietary modification in most patients with diverticulitis who are managed nonoperatively. B Nonsteroidal anti-inflammatory drugs: consider advising patients with a history of diverticulitis to avoid the use of nonsteroidal anti-inflammatoy drugs other than aspirin, if possible. C 5. Inpatient care Bowel rest: advise dietary restriction and bowel rest in patients with acute diverticulitis who display an inflammatory response without abscess formation or bowel perforation. B 6. Nonpharmacologic interventions Dietary modifications: As per ASCRS 2020 guidelines, advise reduced meat intake to potentially reduce the risk of diverticulitis. B As per ESCP 2020 guidelines: Insufficient evidence to support dietary restrictions in patients with acute diverticulitis. Prefer an unrestricted diet when tolerated. I Insufficient evidence to support a high-fiber diet for the sole purpose of prevention of recurrent episodes or persistent symptoms in patients with acute diverticulitis, although it may be recommendable for general health purposes. I As per AGA 2015 guidelines, consider a fiber-rich diet or fiber supplementation in patients with a history of acute diverticulitis. C Smoking cessation: advise smoking cessation to potentially reduce the risk of diverticulitis. B Physical activity: As per ASCRS 2020 guidelines, advise physical activity to potentially reduce the risk of diverticulitis. B As per AGA 2015 guidelines, consider advising patients with diverticular disease to undertake vigorous physical activity. C Weight loss: advise weight loss to potentially reduce the risk of diverticulitis. B Bed rest: insufficient evidence to recommend bed rest in patients with acute diverticulitis. Avoid bed rest since imposed physical inactivity may impair the patient's general condition. I 7. Therapeutic procedures https://web.pathway.md/diseases/rec3Z5lhIppiQuZrO 5/13 6/23/23, 1:44 AM Acute diverticulitis Pathway Percutaneous drainage of diverticular abscesses: As per ASCRS 2020 guidelines, perform image-guided percutaneous drainage in stable patients with abscesses > 3 cm in size. B As per ESCP 2020 guidelines, consider performing percutaneous drainage of abscesses in patients with an abscess > 3 cm, although the role of this procedure in acute diverticulitis is not completely clear. Reserve emergency surgery as last resort for patients failing other non- surgical treatments. C As per WSES 2020 guidelines, consider percutaneous drainage combined with antibiotic therapy in patients with large abscesses. C As per ASCRS 2014 guidelines, perform image-guided percutaneous drainage in stable patients with large diverticular abscesses. B Laparoscopic lavage and drainage: As per ASCRS 2020 guidelines: Do not perform laparoscopic lavage in patients with feculent peritonitis. Perform colectomy in this situation. D Prefer colectomy over laparoscopic lavage in patients with purulent peritonitis, as laparoscopic lavage is associated with higher rates of secondary intervention in comparison with colectomy. A As per ESCP 2020 guidelines, consider performing laparoscopic lavage in selected patients with Hinchey III peritonitis. Alternatively, perform a resection. C As per WSES 2020 guidelines, consider laparoscopic peritoneal lavage and drainage only in very selected patients with generalized peritonitis, but not as first-line therapy in patients with peritonitis from acute colonic diverticulitis. B 8. Perioperative care Postoperative antibiotic therapy: consider a 4-day postoperative antibiotic therapy in patients with complicated acute left-sided colonic diverticulitis if source control has been adequate. C 9. Surgical interventions Emergency colectomy: As per DGVS 2022 guidelines, consider performing surgical exploration, possibly with colectomy (dissection at the terminal ileum and in the upper third of the rectum), in the threatening situation of severe active bleeding that cannot be either endoscopically or angiographically located. E As per ASCRS 2020 guidelines, perform urgent sigmoid colectomy in patients with diffuse peritonitis or when nonoperative management of acute diverticulitis fails. B Show 3 more https://web.pathway.md/diseases/rec3Z5lhIppiQuZrO 6/13 6/23/23, 1:44 AM Acute diverticulitis Pathway As per ESCP 2020 guidelines, consider performing immediate surgery in hemodynamically unstable or septic patients with diverticulitis. C Show 2 more As per WSES 2020 guidelines, consider performing emergency laparoscopic sigmoidectomy in patients with diffuse peritonitis due to perforated diverticulitis only if technical skills and equipment are available. C As per JGA 2019 guidelines: Perform emergency surgery for colonic diverticulitis in patients presenting with generalized peritonitis. A Perform colectomy when antibiotic therapy and drainage are ineffective in patients with complicated diverticulitis. B As per ASCRS 2014 guidelines, perform urgent sigmoid colectomy in patients with diffuse peritonitis, or if nonoperative management of acute diverticulitis fails. B Elective colectomy: As per DGVS 2022 guidelines, consider performing elective partial colectomy during the remission interval in patients with recurrent, hemodynamically effective diverticular hemorrhage and a need for lifelong anticoagulation. E As per ASCRS 2020 guidelines, perform elective colectomy in patients with diverticulitis complicated by fistula, obstruction, or stricture. B Show 6 more As per ESCP 2020 guidelines, avoid performing elective surgery to prevent complicated disease, irrespective of the number of previous attacks. D Show 5 more As per WSES 2020 guidelines: Consider evaluating patient-related factors and not number of previous episodes of diverticulitis in planning elective sigmoid resection. C Consider planning an elective sigmoid resection after an episode of acute left-sided colonic diverticulitis treated conservatively in high-risk patients, such as immunocompromised patients. C As per JGA 2019 guidelines, consider performing elective colectomy in selected patients with recurrent colonic diverticulitis without abscess or perforation, such as in immunocompromised patients. C As per AGA 2015 guidelines, avoid performing routine elective prophylactic colonic resection in patients with an initial episode of acute uncomplicated diverticulitis. D As per ASCRS 2014 guidelines, individualize the decision to recommend elective sigmoid colectomy after recovery from uncomplicated acute diverticulitis. B Technical considerations for surgery: As per DGVS 2022 guidelines, consider performing segmental resection if diverticular bleeding is recurrent or not to stop but clearly localizable. E https://web.pathway.md/diseases/rec3Z5lhIppiQuZrO 7/13 6/23/23, 1:44 AM Acute diverticulitis Pathway As per ESCP 2020 guidelines, decide on surgical approach in patients with fecal peritonitis based on the experience of the surgeon. Insufficient evidence to support laparoscopic over open surgery. Perform resection as the treatment of choice. B Show 7 more As per WSES 2020 guidelines, perform Hartmann's procedure for the management of diffuse peritonitis in critically ill patients and in selected patients with multiple comorbidities. B Show 2 more As per ASCRS 2014 guidelines, resect the entire sigmoid colon with margins of healthy colon and rectum in patients in whom an elective surgical approach is undertaken. B Show 5 more 10. Specific circumstances Patients with complicated diverticulitis (general indications): Consider antibiotic therapy and bowel rest in patients with complicated colonic diverticulitis, localized peritonitis, and an abscess 3 cm. Consider ultrasound- or CT-guided drainage in patients with an abscess 5 cm. Individualize treatment based on clinical status, feasibility of drainage, and resource availability in patients with an abscess 3-5 cm. C Perform colectomy when antibiotic therapy and drainage are ineffective. B Patients with complicated diverticulitis, abscess and localized peritonitis: As per ASCRS 2020 guidelines: Perform image-guided percutaneous drainage in stable patients with abscesses > 3 cm in size. B Consider elective resection after successful nonoperative treatment of a diverticular abscess. B As per ESCP 2020 guidelines: Consider performing percutaneous drainage of abscesses in patients with an abscess > 3 cm, although the role of this procedure in acute diverticulitis is not completely clear. Reserve emergency surgery as last resort for patients failing other non-surgical treatments. C Consider performing laparoscopic or open resection of the diseased bowel with or without anastomosis in patients with persistent abscesses. C As per WSES 2020 guidelines, consider an initial trial of nonoperative treatment with antibiotics alone in patients with a small (< 4-5 cm) diverticular abscess. C Show 2 more As per JGA 2019 guidelines, consider antibiotic therapy and bowel rest as first-line therapy in patients with complicated colonic diverticulitis with abscess and localized peritonitis when the abscess measures 3 cm. However, consider instituting ultrasound or CT-guided drainage, antibiotic therapy, and bowel rest if it measures 5 cm. For abscesses measuring 3-5 cm, consider individualized treatment based on disease state and feasibility of drainage depending on the availability of human and facility sources. C https://web.pathway.md/diseases/rec3Z5lhIppiQuZrO 8/13 6/23/23, 1:44 AM Acute diverticulitis Pathway Show 2 more Patients with complicated diverticulitis, fistula: As per ESCP 2020 guidelines, consider performing laparoscopic or open resection of the diseased bowel with or without anastomosis in patients with fistulas. C As per JGA 2019 guidelines, perform colectomy for complicated colonic diverticulitis with fistulization between the colon and other organs due to diverticula. B Patients with complicated diverticulitis (stricture): perform colectomy in patients with complicated colonic diverticulitis with stricture that develops after remission of colonic diverticulitis. B Elderly patients (diagnosis): avoid basing the diagnosis of acute left colonic diverticulitis in elderly patients solely on patient clinical signs, symptoms and laboratory tests. D Elderly patients (diagnostic imaging): consider obtaining appropriate imaging for suspected diverticulitis in elderly patients presenting with abdominal guarding or pain in the lower left abdomen on physical examination, regardless of the value of WBCs and of CRP. C Show 2 more Elderly patients (indications for non-operative management): Avoid offering nonoperative management as a viable option in elderly patients with acute left colonic diverticulitis and CT findings of distant intraperitoneal free air and no free fluid (WSES stage 2b). D Do not offer nonoperative management as a viable option in elderly patients with acute left colonic diverticulitis and diffuse peritonitis (WSES stage 3-4). D Elderly patients (antibiotic therapy): avoid administering antibiotic therapy in immunocompetent elderly patients with uncomplicated left colonic diverticulitis (WSES stage 0) without sepsis-related organ failures. D Show 5 more Elderly patients (percutaneous drainage of diverticular abscesses): Consider performing percutaneous drainage in addition to antibiotic therapy in elderly patients with acute left colonic diverticulitis and an abscess > 4 cm (WSES stage 2a), when skills and facilities are available. C Obtain cultures from percutaneous drainage to guide the antibiotic therapy. B Elderly patients (laparoscopic lavage and drainage): avoid performing laparoscopic lavage as the preferred surgical approach in elderly patients with acute left colonic diverticulitis and acute peritonitis because of the higher risk of failure to control the source of sepsis. D Elderly patients (emergency colectomy): perform prompt and effective source control surgery in elderly patients with acute left colonic diverticulitis and diffuse peritonitis (WSES stage 3-4). B Show 3 more Elderly patients (elective colectomy): avoid performing elective sigmoid resection after a conservatively treated episode of acute left colonic diverticulitis in asymptomatic elderly patients without stenosis, fistulae or recurrent diverticular bleeding. D https://web.pathway.md/diseases/rec3Z5lhIppiQuZrO 9/13 6/23/23, 1:44 AM Acute diverticulitis Pathway Show 3 more Elderly patients (follow-up): Consider planning early colonic evaluation in elderly patients after an episode of acute left colonic diverticulitis. C Obtain further diagnostic investigation in elderly patients with complicated diverticulitis with ongoing signs of peritonitis or systemic illness (ongoing infection) beyond 5-7 days of antibiotic treatment. B 11. Preventative measures Aminosalicylates: As per ASCRS 2020 guidelines, do not offer mesalamine for reducing the risk of diverticulitis recurrence, but consider for reducing chronic symptoms. D As per ESCP 2020 guidelines, do not offer mesalazine for the prevention of recurrent diverticulitis or persistent complaints after an episode of acute diverticulitis. D As per AGA 2015 guidelines, avoid the use of mesalamine after acute uncomplicated diverticulitis. D Rifaximin: As per ASCRS 2020 guidelines, do not offer rifaximin for reducing the risk of diverticulitis recurrence, but consider for reducing chronic symptoms. D As per ESCP 2020 guidelines, do not offer rifaximin for the prevention of recurrent diverticulitis or persistent complaints after an episode of acute diverticulitis. D As per AGA 2015 guidelines, consider avoiding the use of rifaximin after acute uncomplicated diverticulitis. D Probiotics: As per ASCRS 2020 guidelines, do not offer probiotics for reducing the risk of diverticulitis recurrence, but consider for reducing chronic symptoms. D As per ESCP 2020 guidelines, do not offer probiotics for the prevention of recurrent diverticulitis or persistent complaints after an episode of acute diverticulitis. D As per AGA 2015 guidelines, consider avoiding the use of probiotics after acute uncomplicated diverticulitis. D Secondary prevention: insufficient evidence to recommend any interventions for secondary prevention. I 12. Follow-up and surveillance Follow-up: As per ESCP 2020 guidelines, avoid obtaining endoscopic follow-up in patients with symptom- free recovery after a single episode of CT-verified uncomplicated diverticulitis. Follow-up all https://web.pathway.md/diseases/rec3Z5lhIppiQuZrO 10/13 6/23/23, 1:44 AM Acute diverticulitis Pathway other patients treated without resection for acute diverticulitis with an examination of the colon at least 6 weeks after the acute episode, if not done within the last 3 years. D As per WSES 2020 guidelines: Consider planning an early colonic evaluation (4-6 weeks) in patients with diverticular abscesses treated nonoperatively. C Do not perform routine colonic evaluation in patients with CT-proven uncomplicated diverticulitis treated nonoperatively. D As per JGA 2019 guidelines, perform colonoscopy at least once to eliminate the possibility of lesions other than colonic diverticulosis as the possible cause of disease, although the association between colonic diverticulitis and colorectal cancer is currently unknown. B As per AGA 2015 guidelines, consider performing a follow-up colonoscopy after resolution of acute diverticulitis, in appropriate candidates, to exclude the misdiagnosis of a colonic neoplasm if a high-quality examination of the colon has not been recently performed. C As per ASCRS 2014 guidelines, perform a follow-up colonoscopy after resolution of acute diverticulitis to confirm the diagnosis if this is the first episode, or recent colonoscopy has not been performed. B Management of recurrent diverticulitis: consider conservative treatment when recurrent colonic diverticulitis is not accompanied by abscess. When abscess is present, however, treat as a first episode of diverticulitis. C Likelihood Ratios Pertinent positives The following findings increase the probability of acute diverticulitis in adults. 15 Finding LR+ Value Presence of findings of diverticulitis* 94 Presence of LLQ tenderness 10.4 History of LLQ pain 3.3 Increased serum CRP 2.2 diverticulae, bowel wall thickening, pericolic fat stranding Show 1 more Pertinent negatives The following findings decrease the probability of acute diverticulitis in adults. 15 https://web.pathway.md/diseases/rec3Z5lhIppiQuZrO 11/13 6/23/23, 1:44 AM Acute diverticulitis Pathway LR- * diverticulae, bowel wall thickening, pericolic fat stranding 0.1 Finding Value Absence of findings of diverticulitis* Show 1 more serum CRP not increased 0.3 No history of LLQ pain References Absence of LLQ tenderness 0.5 0.7 1. Paola Fugazzola, Marco Ceresoli, Federico Coccolini et al. The WSES/SICG/ACOI/SICUT/AcEMC/SIFIPAC guidelines for diagnosis and treatment of acute left colonic diverticulitis in the elderly. World J Emerg Surg. 2022 Jan 21;17 1 5. Open 2. J K Schultz, N Azhar, G A Binda et al. European Society of Coloproctology: guidelines for the management of diverticular disease of the colon. Colorectal Dis. 2020 Sep;22 Suppl 2 5 28. Open 3. Massimo Sartelli, Dieter G Weber, Yoram Kluger et al. 2020 update of the WSES guidelines for the management of acute colonic diverticulitis in the emergency setting. World J Emerg Surg. 2020 May 7;15 1 32. Open 4. Stollman N, Smalley W, Hirano I. American Gastroenterological Association Institute Guideline on the Management of Acute Diverticulitis. Gastroenterology. 2015 Dec;149 7 1944 9. Open 5. Nagata N, Ishii N, Manabe N et al. Guidelines for Colonic Diverticular Bleeding and Colonic Diverticulitis: Japan Gastroenterological Association. Digestion. 2019;99 Suppl 1 1 26. Open 6. Jason Hall, Karin Hardiman, Sang Lee et al. The American Society of Colon and Rectal Surgeons Clinical Practice Guidelines for the Treatment of Left-Sided Colonic Diverticulitis. Dis Colon Rectum. 2020 Jun;63 6 728 747. Open 7. Wolfgang Kruis, Christoph-Thomas Germer, Stephan B hm et al. German guideline diverticular disease/diverticulitis Part I Methods, pathogenesis, epidemiology, clinical characteristics (definitions), natural course, diagnosis and classification. United European Gastroenterol J. 2022 Nov 21. Open 8. Feingold D, Steele SR, Lee S et al. Practice parameters for the treatment of sigmoid diverticulitis. Dis Colon Rectum. 2014 Mar;57 3 284 94. Open 9. Amir Qaseem, Itziar Etxeandia-Ikobaltzeta, Jennifer S Lin et al. Diagnosis and Management of Acute Left-Sided Colonic Diverticulitis: A Clinical Guideline From the American College of Physicians. Ann Intern Med. 2022 Jan 18. Online ahead of print. Open 10. Stefanie Weinstein, MDa, David H. Kim et al. ACR Appropriateness Criteria Left Lower Quadrant Pain. ACR. 2023. Open 11. Expert Panel on Gastrointestinal Imaging, Avinash R Kambadakone, Cynthia S Santillan et al. ACR Appropriateness Criteria Right Lower Quadrant Pain: 2022 Update. J Am Coll Radiol. 2022 Nov;19 11S S445 S461. Open 12. Feuerstein JD, Falchuk KR. Diverticulosis and Diverticulitis. Mayo Clin Proc. 2016 Aug;91 8 1094 104. Open 13. Adil E Bharucha, Gopanandan Parthasarathy, Ivo Ditah et al. Temporal Trends in the Incidence and Natural History of Diverticulitis: A Population-Based Study. Am J Gastroenterol. 2015 Nov;110 11 1589 96. Open 14. Schieffer KM, Kline BP, Yochum GS et al. Pathophysiology of diverticular disease. Expert Rev Gastroenterol Hepatol. 2018 Jul;12 7 683 692. Open https://web.pathway.md/diseases/rec3Z5lhIppiQuZrO 12/13 6/23/23, 1:44 AM Acute diverticulitis Pathway 15. Young-Fadok TM. Diverticulitis. N Engl J Med. 2018 Oct 25;379 17 1635 1642. Open 16. Thad Wilkins, Katherine Embry, Ruth George. Diagnosis and Management of Acute Diverticulitis. Am Fam Physician. 2013 May 1;87 9 612 20. Open 17. Sophia M Swanson, Lisa L Strate. Acute Colonic Diverticulitis. Ann Intern Med. 2018 May 1;168 9 ITC65 ITC80. Open 18. Lisa L Strate, Arden M Morris. Epidemiology, Pathophysiology, and Treatment of Diverticulitis. Gastroenterology. 2019 Apr;156 5 1282 1298.e1. Open 19. Catherine D. Linzay, Sudha Pandit. Acute Diverticulitis. In: StatPearls Internet]. Treasure Island FL StatPearls Publishing; 2020 Jan. 2020 Nov 20. Open 20. Laura Mora-L pez, Neus Ruiz-Edo, Oscar Estrada-Ferrer et al. Efficacy and Safety of Nonantibiotic Outpatient Treatment in Mild Acute Diverticulitis DINAMO-study): A Multicentre, Randomised, Open-label, Noninferiority Trial. Ann Surg. 2021 Nov 1;274 5):e435-e442. Open https://web.pathway.md/diseases/rec3Z5lhIppiQuZrO 13/13