~51 spots leftby Oct 2026

Surgery vs Medicine for Diverticulitis

(COSMID Trial)

Recruiting at27 trial locations
DR
Overseen byDavid R Flum, MD
Age: 18+
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Academic
Recruiting
Sponsor: University of Washington
Must not be taking: Immunosuppressants, IBD meds, IBS meds
Disqualifiers: Liver failure, Renal failure, Malignancy, others
No Placebo Group

Trial Summary

What is the purpose of this trial?

This trial compares surgery (removing part of the colon) with a combination of medications and lifestyle changes for patients whose diverticular disease affects their quality of life. It aims to find out which treatment helps these patients feel better and live more comfortably.

Do I need to stop my current medications for the trial?

The trial protocol does not specify if you need to stop taking your current medications. However, if you are taking medications for inflammatory bowel disease or irritable bowel syndrome, you may not be eligible to participate.

What data supports the effectiveness of this treatment for diverticulitis?

Recent studies suggest that non-surgical management, which includes medical and conservative treatments, can be as effective as surgery for many patients with uncomplicated diverticulitis. However, surgery may still be necessary for those with complicated cases or for immunocompromised patients, where medical treatment often fails.12345

Is surgery or medical management for diverticulitis safe?

Research suggests that non-surgical management, which includes antibiotics and supportive care, is safe for over 70% of patients with diverticulitis. For those needing surgery, minimally invasive procedures like laparoscopic colectomy have shown improved safety outcomes, especially in patients with other health issues.678910

How does the treatment of surgery vs medicine for diverticulitis differ from other treatments?

This treatment is unique because it compares medical management, which often involves antibiotics and dietary changes, with surgical options like partial colectomy (removal of part of the colon), which is typically reserved for patients with a high risk of recurrence or when conservative treatments fail. The choice between these approaches depends on the severity of the condition and the patient's overall health.25111213

Research Team

DR

David R Flum, MD

Principal Investigator

University of Washington

Eligibility Criteria

Adults over 18 with a history of recurrent diverticulitis confirmed by CT and colonoscopy, who are currently symptom-free or have persistent symptoms for more than 3 months after an episode. Not eligible if they have right-sided diverticulitis, take certain medications for bowel diseases, had previous surgeries for diverticulitis, are pregnant or planning to become pregnant soon, or have conditions that rule out surgery.

Inclusion Criteria

I have had at least one confirmed diverticulitis episode and a colonoscopy.
I have a history of simple diverticulitis without current symptoms or ongoing issues related to diverticular disease.
I am 18 years old or older.

Exclusion Criteria

Prior enrollment in the study or other investigational drug or vaccine while on study treatment
I do not have conditions like liver or kidney failure that prevent surgery.
I am on medication for Crohn's disease or ulcerative colitis.
See 10 more

Trial Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants are randomized to either elective segmental colectomy or best medical management

6 weeks
1 visit (in-person) for surgery, multiple visits for medical management

Follow-up

Participants are monitored for quality of life and symptoms using the GIQLI at 6, 9, and 12 months

12 months
3 visits (in-person or virtual) at 6, 9, and 12 months

Treatment Details

Interventions

  • Medical Management (NA)
  • Partial Colectomy (NA)
Trial OverviewThe COSMID trial is testing whether elective colectomy (a type of surgery) is more effective than the best medical management in improving quality of life for patients with problematic diverticular disease. Patients will either undergo surgery or receive medical treatment based on random assignment.
Participant Groups
2Treatment groups
Active Control
Group I: Partial ColectomyActive Control1 Intervention
Elective segmental colectomy for diverticular disease involves removal of the segment of colon (most commonly sigmoid and/or left colon) where there has been disease identified by computed tomography imaging or colonoscopy. Elective colectomy usually removes the affected colon along with adjacent segments that have diverticula, with a primary anastomosis performed to reestablish bowel continuity. Most surgeons now perform the procedure using a laparoscopic approach, when possible, and sometimes use a temporary, protective stoma if the re-connection is considered high-risk. The technique for laparoscopic resection is not specified by the protocol (allows for any number of laparoscopic port sites, all incision types, hand-assistance and robotic) with details of the technique recorded. If randomized to elective colectomy, patients will be encouraged to undergo the procedure within 6 weeks of assignment.
Group II: Medical ManagementActive Control1 Intervention
Medical management for diverticular disease has been used for over 30 years and includes a set of interventions, all components of which have been the subject of small, but often positive trials. All patients randomized to medical management or who select it as their treatment in the observational cohort will view a video (provided in English and Spanish) that explains each element of the medical management "toolbox": diet and exercise recommendations, fiber supplementation (e.g., augmenting dietary fiber or over the counter fiber supplements), with mesalazine tablets or suppositories, probiotics and rifamycin. In consultation with their physician, they will be recommended to a regimen of diet and exercise and fiber supplementation. Clinicians will be asked to consider rifamycin (dose/frequency) for those with AUD who are not responding to diet and exercise and mesalazine (dose/frequency) for those with lingering symptoms who are not responding to diet and exercise.

Find a Clinic Near You

Who Is Running the Clinical Trial?

University of Washington

Lead Sponsor

Trials
1,858
Recruited
2,023,000+

Dr. Timothy H. Dellit

University of Washington

Chief Executive Officer since 2023

MD from University of Washington

Dr. Anneliese Schleyer

University of Washington

Chief Medical Officer since 2023

MD, MHA

Patient-Centered Outcomes Research Institute

Collaborator

Trials
592
Recruited
27,110,000+
Nakela L. Cook profile image

Nakela L. Cook

Patient-Centered Outcomes Research Institute

Chief Executive Officer since 2020

MD, MPH

Harv Feldman profile image

Harv Feldman

Patient-Centered Outcomes Research Institute

Chief Medical Officer

MD, MSCE

Findings from Research

Diverticulitis has become a common reason for hospitalizations related to the gastrointestinal tract, with cases ranging from mild to severe, complicated forms.
Recent studies suggest that nonoperative management of diverticulitis may provide outcomes that are equal to or better than traditional aggressive surgical approaches, indicating a shift in treatment strategies.
Management of Diverticulitis in 2017.Deery, SE., Hodin, RA.[2018]
In a study of 86 patients (76 nonimmunocompromised and 10 immunocompromised), medical therapy was successful in 76% of nonimmunocompromised patients, while it failed completely in immunocompromised patients, highlighting the need for a high index of suspicion for diagnosis in this group.
All immunocompromised patients required surgery for acute diverticulitis, with colostomy and resection showing fewer complications compared to colostomy and drainage, suggesting it may be the preferred surgical approach for these patients.
Acute diverticulitis. Comparison of treatment in immunocompromised and nonimmunocompromised patients.Perkins, JD., Shield, CF., Chang, FC., et al.[2019]
Nonoperative management is effective for treating uncomplicated right colonic diverticulitis, with a low recurrence rate of only 1% among 276 patients treated for inflamed diverticulum or phlegmon.
In contrast, patients with pericolic abscesses had a higher recurrence rate of 20%, indicating that this condition may require more careful management and possibly surgical intervention.
Nonoperative management of right colonic diverticulitis using radiologic evaluation.Park, HC., Chang, MY., Lee, BH.[2016]

References

Management of Diverticulitis in 2017. [2018]
Acute diverticulitis. Comparison of treatment in immunocompromised and nonimmunocompromised patients. [2019]
Nonoperative management of right colonic diverticulitis using radiologic evaluation. [2016]
Elective Surgery for Sigmoid Diverticulitis - Indications, Techniques, and Results. [2020]
Comparative outcomes of acute colonic diverticulitis in immunocompromised versus immunocompetent patients: a systematic review and meta-analysis. [2023]
Meta-analyses of Current Strategies to Treat Uncomplicated Diverticulitis. [2019]
Laparoscopic colectomy for diverticulitis in patients with pre-operative respiratory comorbidity: analysis of post-operative outcomes in the United States from 2005 to 2017. [2022]
The Decline of Elective Colectomy Following Diverticulitis: A Population-Based Analysis. [2016]
Update on the management of sigmoid diverticulitis. [2021]
10.Korea (South)pubmed.ncbi.nlm.nih.gov
Treatment of right colonic diverticulitis: the role of nonoperative treatment. [2021]
11.United Statespubmed.ncbi.nlm.nih.gov
Drains, Germs, or Steel: Multidisciplinary Management of Acute Colonic Diverticulitis. [2021]
12.United Statespubmed.ncbi.nlm.nih.gov
Medical treatment of diverticular disease. [2021]
13.United Statespubmed.ncbi.nlm.nih.gov
Diverticulosis and acute diverticulitis. [2022]