IDEAS AND OPINIONS
Annals of Internal Medicine
Acute Uncomplicated Diverticulitis: What to Do Until We Have Better Data Robert M. Centor, MD
A
cute uncomplicated diverticulitis occurs in approximately 4% of patients with diverticulosis. Outpatient, acute care, and inpatient physicians all participate in their care. The American Gastroenterological Association (AGA) has developed a new guideline on this subject (updating a previous guideline from 1999) (1). Before considering these guidelines, we must clearly define acute uncomplicated diverticulitis. The definition requires a computed tomography scan that documents the lack of abscesses or fistulas. Patients with clinical findings of severe infection or sepsis have complicated diverticulitis. Patients with risk factors for more severe disease, such as immunosuppression, or significant comorbidities do not fit the definition. This guideline does not apply to those more complicated patients. Mention acute uncomplicated diverticulitis to most internists, and their immediate reflex is to prescribe antibiotics, either outpatient or inpatient, depending on a subjective assessment of the patient's condition. Recent articles have challenged this concept, suggesting that most acute uncomplicated diverticulitis is an inflammatory reaction rather than an acute infection. In a recent study, 155 patients with acute uncomplicated diverticulitis received conservative outpatient management without antibiotics (2). Only 4 (2.6%) patients required admission: 3 for complications and 1 for deterioration. All 4 had successful inpatient treatment without the need for surgery. A randomized, controlled trial published in 2012 studied 623 patients with acute uncomplicated diverticulitis confirmed via computed tomography: 314 patients received antibiotics and 309 patients did not (3). The investigators found no statistical difference in length of hospitalization (3 days), perforation or abscess formation, or recurrent diverticulitis within 1 year (16%). These and other studies support avoiding antibiotics in this specific subset of patients; however, a careful technical review of the available literature graded the evidence quality as very low. Thus, AGA can rate a recommendation to withhold antibiotics only as conditional. If we could eschew antibiotic therapy for this condition, we could possibly decrease antibiotic complications. However, most hospitalists will require very strong evidence before changing their therapeutic strategy. The guideline also addresses many other possibilities for acute treatment or prevention. Possible acute treatments considered include surgery, mesalamine, rifaximin, or probiotics. Possible prevention strategies in-
This article was published at www.annals.org on 19 November 2015. 120 © 2016 American College of Physicians
Downloaded From: http://annals.org/ by a University of Otago User on 12/11/2016
clude colonoscopy (looking for colon cancer); a fiberrich diet; avoidance of seeds, nuts, popcorn, aspirin, and nonsteroidal anti-inflammatory drugs (NSAIDs); and engaging in vigorous physical activity. Unfortunately, as the AGA Institute examined a careful literature review, the evidence quality did not meet a sufficient standard to develop strong recommendations, with the exception of the evidence against using mesalamine for treating acute uncomplicated diverticulitis. AGA does give conditional recommendations against using rifaximin or probiotics to treat acute uncomplicated diverticulitis. It conditionally recommends against surgical resection but favors following resolution with colonoscopy (assuming no recent colonoscopy). AGA also conditionally suggests a highfiber diet and recommends against restricting nuts, seeds, or popcorn. It does not recommend avoiding aspirin but does suggest avoiding NSAIDs if possible. All of these recommendations are conditional—another way of saying that the evidence base has not yet reached a sufficient standard to make definitive recommendations. Thus, we should consider the current guideline as expert opinion based on very-low-quality evidence. We should not develop performance measures from this guideline, because the recommendations need further research. The guideline committee recognized this problem with this statement: The majority of the evidence currently, however, is of poor quality, and most of our recommendations are therefore conditional. Areas that should be priorities for future research include: • Identifying patients who will benefit from antibiotics and those in whom they can safely be withheld. • Evaluating medical therapies, such as antiinflammatories, antibiotics or probiotics, and dietary interventions that may decrease symptoms, complications, and/or reduce recurrence rates after acute diverticulitis. • Identifying risk factors for recurrent diverticulitis, to better target potential medical interventions to populations most likely to benefit. • Quantifying the yield, risks and timing of colonoscopy after an episode of acute diverticulitis.
IDEAS AND OPINIONS
Acute Uncomplicated Diverticulitis
This guideline provides an important view into our understanding of diverticulitis treatment and avoidance. We have inadequate data to support the development of an evidence-based protocol for these patients. We commend the AGA for the careful methods used in developing the guideline. Its inclusion of research priorities will hopefully stimulate more research for this common presentation. We have not received a charge to change our practices, but rather a careful explication of what data we need. If we read this guideline as intended, we will learn that acute uncomplicated diverticulitis has not received adequate study. Knowing that explicitly helps us as clinicians. From the University of Alabama School of Medicine Huntsville Regional Medical Campus, Huntsville, Alabama. Disclosures: The author has disclosed no conflicts of interest.
Forms can be viewed at www.acponline.org/authors/icmje /ConflictOfInterestForms.do?msNum=M15-2499.
Requests for Single Reprints: Robert M. Centor, MD, Regional Dean, UAB Huntsville Regional Medical Campus, 301 Governors Drive, Huntsville, AL 35801; e-mail, [email protected].
Author contributions are available at www.annals.org. Ann Intern Med. 2016;164:120-121. doi:10.7326/M15-2499
References 1. Stollman N, Smalley W, Hirano I; AGA Institute Clinical Guidelines Committee. American Gastroenterological Association Institute Guideline on the Management of Acute Diverticulitis. Gastroenterology. 2015. [PMID: 26453777] 2. Isacson D, Thorisson A, Andreasson K, Nikberg M, Smedh K, Chabok A. Outpatient, non-antibiotic management in acute uncomplicated diverticulitis: a prospective study. Int J Colorectal Dis. 2015; 30:1229-34. [PMID: 25989930] 3. Chabok A, Påhlman L, Hjern F, Haapaniemi S, Smedh K; AVOD Study Group. Randomized clinical trial of antibiotics in acute uncomplicated diverticulitis. Br J Surg. 2012;99:532-9. [PMID: 22290281] doi:10.1002/bjs.8688
ANNALS VIRTUAL PATIENTS Annals Virtual Patients are online interactive cases that mirror real patient care decisions and their consequences, while earning you CME credit and MOC points. Visit www.annals.org/virtualpatients to try a free case to see where your decisions take you.
www.annals.org
Downloaded From: http://annals.org/ by a University of Otago User on 12/11/2016
Annals of Internal Medicine • Vol. 164 No. 2 • 19 January 2016 121
Annals of Internal Medicine Author Contributions: Conception and design: R.M. Centor.
Drafting of the article: R.M. Centor. Final approval of the article: R.M. Centor. Administrative, technical, or logistic support: R.M. Centor.
www.annals.org
Downloaded From: http://annals.org/ by a University of Otago User on 12/11/2016
Annals of Internal Medicine • Vol. 164 No. 2 • 19 January 2016
Annals of Internal Medicine
Acute Uncomplicated Diverticulitis: What to Do Until We Have Better Data Robert M. Centor, MD
A
cute uncomplicated diverticulitis occurs in approximately 4% of patients with diverticulosis. Outpatient, acute care, and inpatient physicians all participate in their care. The American Gastroenterological Association (AGA) has developed a new guideline on this subject (updating a previous guideline from 1999) (1). Before considering these guidelines, we must clearly define acute uncomplicated diverticulitis. The definition requires a computed tomography scan that documents the lack of abscesses or fistulas. Patients with clinical findings of severe infection or sepsis have complicated diverticulitis. Patients with risk factors for more severe disease, such as immunosuppression, or significant comorbidities do not fit the definition. This guideline does not apply to those more complicated patients. Mention acute uncomplicated diverticulitis to most internists, and their immediate reflex is to prescribe antibiotics, either outpatient or inpatient, depending on a subjective assessment of the patient's condition. Recent articles have challenged this concept, suggesting that most acute uncomplicated diverticulitis is an inflammatory reaction rather than an acute infection. In a recent study, 155 patients with acute uncomplicated diverticulitis received conservative outpatient management without antibiotics (2). Only 4 (2.6%) patients required admission: 3 for complications and 1 for deterioration. All 4 had successful inpatient treatment without the need for surgery. A randomized, controlled trial published in 2012 studied 623 patients with acute uncomplicated diverticulitis confirmed via computed tomography: 314 patients received antibiotics and 309 patients did not (3). The investigators found no statistical difference in length of hospitalization (3 days), perforation or abscess formation, or recurrent diverticulitis within 1 year (16%). These and other studies support avoiding antibiotics in this specific subset of patients; however, a careful technical review of the available literature graded the evidence quality as very low. Thus, AGA can rate a recommendation to withhold antibiotics only as conditional. If we could eschew antibiotic therapy for this condition, we could possibly decrease antibiotic complications. However, most hospitalists will require very strong evidence before changing their therapeutic strategy. The guideline also addresses many other possibilities for acute treatment or prevention. Possible acute treatments considered include surgery, mesalamine, rifaximin, or probiotics. Possible prevention strategies in-
This article was published at www.annals.org on 19 November 2015. 120 © 2016 American College of Physicians
Downloaded From: http://annals.org/ by a University of Otago User on 12/11/2016
clude colonoscopy (looking for colon cancer); a fiberrich diet; avoidance of seeds, nuts, popcorn, aspirin, and nonsteroidal anti-inflammatory drugs (NSAIDs); and engaging in vigorous physical activity. Unfortunately, as the AGA Institute examined a careful literature review, the evidence quality did not meet a sufficient standard to develop strong recommendations, with the exception of the evidence against using mesalamine for treating acute uncomplicated diverticulitis. AGA does give conditional recommendations against using rifaximin or probiotics to treat acute uncomplicated diverticulitis. It conditionally recommends against surgical resection but favors following resolution with colonoscopy (assuming no recent colonoscopy). AGA also conditionally suggests a highfiber diet and recommends against restricting nuts, seeds, or popcorn. It does not recommend avoiding aspirin but does suggest avoiding NSAIDs if possible. All of these recommendations are conditional—another way of saying that the evidence base has not yet reached a sufficient standard to make definitive recommendations. Thus, we should consider the current guideline as expert opinion based on very-low-quality evidence. We should not develop performance measures from this guideline, because the recommendations need further research. The guideline committee recognized this problem with this statement: The majority of the evidence currently, however, is of poor quality, and most of our recommendations are therefore conditional. Areas that should be priorities for future research include: • Identifying patients who will benefit from antibiotics and those in whom they can safely be withheld. • Evaluating medical therapies, such as antiinflammatories, antibiotics or probiotics, and dietary interventions that may decrease symptoms, complications, and/or reduce recurrence rates after acute diverticulitis. • Identifying risk factors for recurrent diverticulitis, to better target potential medical interventions to populations most likely to benefit. • Quantifying the yield, risks and timing of colonoscopy after an episode of acute diverticulitis.
IDEAS AND OPINIONS
Acute Uncomplicated Diverticulitis
This guideline provides an important view into our understanding of diverticulitis treatment and avoidance. We have inadequate data to support the development of an evidence-based protocol for these patients. We commend the AGA for the careful methods used in developing the guideline. Its inclusion of research priorities will hopefully stimulate more research for this common presentation. We have not received a charge to change our practices, but rather a careful explication of what data we need. If we read this guideline as intended, we will learn that acute uncomplicated diverticulitis has not received adequate study. Knowing that explicitly helps us as clinicians. From the University of Alabama School of Medicine Huntsville Regional Medical Campus, Huntsville, Alabama. Disclosures: The author has disclosed no conflicts of interest.
Forms can be viewed at www.acponline.org/authors/icmje /ConflictOfInterestForms.do?msNum=M15-2499.
Requests for Single Reprints: Robert M. Centor, MD, Regional Dean, UAB Huntsville Regional Medical Campus, 301 Governors Drive, Huntsville, AL 35801; e-mail, [email protected].
Author contributions are available at www.annals.org. Ann Intern Med. 2016;164:120-121. doi:10.7326/M15-2499
References 1. Stollman N, Smalley W, Hirano I; AGA Institute Clinical Guidelines Committee. American Gastroenterological Association Institute Guideline on the Management of Acute Diverticulitis. Gastroenterology. 2015. [PMID: 26453777] 2. Isacson D, Thorisson A, Andreasson K, Nikberg M, Smedh K, Chabok A. Outpatient, non-antibiotic management in acute uncomplicated diverticulitis: a prospective study. Int J Colorectal Dis. 2015; 30:1229-34. [PMID: 25989930] 3. Chabok A, Påhlman L, Hjern F, Haapaniemi S, Smedh K; AVOD Study Group. Randomized clinical trial of antibiotics in acute uncomplicated diverticulitis. Br J Surg. 2012;99:532-9. [PMID: 22290281] doi:10.1002/bjs.8688
ANNALS VIRTUAL PATIENTS Annals Virtual Patients are online interactive cases that mirror real patient care decisions and their consequences, while earning you CME credit and MOC points. Visit www.annals.org/virtualpatients to try a free case to see where your decisions take you.
www.annals.org
Downloaded From: http://annals.org/ by a University of Otago User on 12/11/2016
Annals of Internal Medicine • Vol. 164 No. 2 • 19 January 2016 121
Annals of Internal Medicine Author Contributions: Conception and design: R.M. Centor.
Drafting of the article: R.M. Centor. Final approval of the article: R.M. Centor. Administrative, technical, or logistic support: R.M. Centor.
www.annals.org
Downloaded From: http://annals.org/ by a University of Otago User on 12/11/2016
Annals of Internal Medicine • Vol. 164 No. 2 • 19 January 2016
