Diverticular disease: diagnosis and management

Why the committee made the recommendations

Diverticulosis is asymptomatic and there are no specific treatments for it. The committee therefore considered making a recommendation about lifestyle and dietary advice to address the common questions asked by newly diagnosed patients on preventing disease progression. However, although some evidence was found on the management of diverticulosis, it did not meet the criteria for inclusion in the review on what is the most clinically and cost-effective management strategy for preventing diverticular disease in people with diverticulosis.

The committee were aware of evidence (which did not meet the review criteria) that vigorous exercise was associated with a reduction in the risk of developing acute diverticulitis. Increased body mass index was also associated with an increased risk of symptomatic disease. In the absence of evidence that could be used to draft recommendations, formal consensus methods and the knowledge and experience of the committee were used instead. The recommendations should be straightforward to implement and may reduce the possibility of developing diverticular disease.

In light of the lack of evidence on this topic, and the need to know what factors might increase the risk of diverticulosis progressing to diverticular disease, the committee considered this an important area for research. They made recommendations for research on risk factors for diverticular disease and on conservative management for preventing diverticular disease.

How the recommendations might affect practice

The recommendations reflect current practice.

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Why the committee made the recommendation

The evidence on symptoms and signs comprised a single study with no clinically important outcomes and was based on a population with diverticulitis rather than diverticular disease. Because of a lack of evidence, recommendations were made using formal consensus methods and the knowledge and expertise of the committee on the most common presentation of diverticular disease.

Most people experience pain on the left side of the abdomen where the diverticula most often occur in the sigmoid colon. For this reason people are often tender in the left lower quadrant. However, it was important to highlight that people of Asian origin may experience right-sided symptoms. Other symptoms are variable but people experience constipation, diarrhoea or both, with occasional rectal bleeds. The symptoms alone are not specific enough to indicate diverticular disease but should be considered in conjunction with intermittent abdominal pain. Symptoms may overlap with conditions such as irritable bowel syndrome, colitis and malignancy.

How the recommendation might affect practice

The recommendation reflects current practice.

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Why the committee made the recommendations

There was no evidence on diagnosing diverticular disease so the guideline committee made recommendations based on their knowledge of current best practice. Where diverticular disease is suspected, current practice is to use imaging or endoscopy to confirm the presence of diverticula or exclude other diseases such as cancer. Patients will often have their bowel investigated by either endoscopy with a flexible sigmoidoscopy or colonoscopy or CT colonography. The committee agreed that these routine endoscopic and radiological investigations can sometimes be organised from primary care but that referral would be needed if this was not available.

How the recommendations might affect practice

The recommendations reflect current practice.

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Why the committee made the recommendations

Very limited evidence was identified on a high fibre diet, antibiotics, aminosalicylates, probiotics, symbiotics and laxatives and there was no evidence on non-steroidal anti-inflammatory drugs (NSAIDs). The evidence that was available didn't help the committee to understand the impact of these interventions on the progression of disease or people's quality of life. The committee used formal consensus methods together with their expertise and knowledge to make recommendations on diet and lifestyle advice and how to manage pain and cramping.

Bulk-forming laxatives are effective as they help to soften the stool and can also help to solidify loose stools in people with constipation. Paracetamol is indicated for pain and the committee highlighted the importance of avoiding NSAIDs and opioid analgesia because of the risk of diverticular perforation. Some people experience abdominal cramping, and anti-spasmodics may help with this.

In line with best practice in antimicrobial stewardship, the committee made a recommendation not to use antibiotics in the absence of acute diverticulitis.

Having a greater understanding of how best to manage symptoms and prevent the disease developing into acute diverticular disease could have a positive impact on a person's health and wellbeing. It could also help avoid potential subsequent treatment costs. The committee therefore made a recommendation for research on management and advice for people with diverticular disease .

These recommendations are about managing the symptoms of diverticular disease rather than preventing progression to acute diverticulitis. However, the development of acute diverticulitis was included as an outcome in this review and in the recommendation for research that was developed, because the committee considered it to be a critical factor for decision making. The committee noted the importance of considering alternative causes and further investigations in people with persistent symptoms or who do not respond to treatment.

How the recommendations might affect practice

The recommendations reflect current practice.

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Why the committee did not make any recommendations

There was no evidence included for this review and the committee were unable to make any recommendations based on their experience or opinion.

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Why the committee made the recommendation

There was no relevant evidence on the symptoms and signs of acute diverticulitis, so recommendations were made using formal consensus methods. The committee thought that clearly defining the symptoms and signs of acute diverticulitis, along with its associated complications, would help clinicians and patients in clearly differentiating these distinct clinical conditions.

Committee members thought that diverticular disease, symptomatic diverticular disease and acute diverticulitis are often used interchangeably, creating confusion about which condition the patient has and therefore what management is appropriate. The recommendation is focused on symptoms and signs that are specific to acute diverticulitis. It is aimed at primary care to support the identification of the condition.

How the recommendation might affect practice

The recommendation reflects current practice.

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Why the committee made the recommendation

There was no relevant evidence on the symptoms and signs of complicated acute diverticulitis, so a recommendation was made using formal consensus methods. The recommendation focuses on symptoms and signs that differentiate uncomplicated from complicated acute diverticulitis. If any of these symptoms and signs are present, same-day hospital assessment is necessary.

How the recommendation might affect practice

The recommendation reflects current practice.

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Why the committee made the recommendations

There was insufficient evidence available on diagnostic tests for people who are not referred for same-day hospital assessment. The committee highlighted the importance of reassessment or referral if the person's symptoms persist or worsen, as this could indicate complicated acute diverticulitis or an alternative diagnosis.

For people with suspected complications of acute diverticulitis referred for urgent same-day hospital assessment, the committee agreed that less costly clinical tests of full blood count and C‑reactive protein (CRP) should be offered initially to identify inflammation. The urea and electrolytes test assesses kidney function, which will help to determine if a contrast CT can be performed. The CT could inform the decision making and help decide which patients should undergo further investigation for acute diverticulitis.

The committee acknowledged that contrast CT is recognised as the gold standard diagnostic test for acute diverticulitis and its complications. They agreed that having an early CT scan to assess for acute diverticulitis would mean that complications could be identified sooner. This would subsequently reduce length of hospital stay and the number of later colonoscopies. In addition, having the scan within 24 hours of admission would also help guide treatment planning. For example, it could identify people with uncomplicated diverticular disease who can be given oral antibiotics and discharged or have antibiotics stopped and be discharged.

Where contrast CT is contraindicated, the committee agreed that non-contrast CT, MRI or ultrasound are accepted alternatives to contrast CT. The choice of whether to perform ultrasound should depend on the availability of local expertise. Ultrasound may not be able to diagnose diverticulitis in isolation, but it may identify factors such as colonic wall thickening and inflammation. Ultrasound may be used as an adjunct to rule out other disease.

There was no evidence for colonoscopy and sigmoidoscopy in diagnosing acute diverticulitis. The committee were aware of the risk of perforation and agreed that these procedures should not be offered for acute diverticulitis.

How the recommendations might affect practice

Full blood count and CRP are routinely used to assess for inflammation and indication of acute diverticulitis. This reflects current best practice but is not used across all NHS settings. Therefore implementing this recommendation will mean a change in practice for some providers.

Currently, 60% of people with acute diverticulitis undergo CT examination to confirm the diagnosis. This recommendation will increase the use of CT scanning. However, the increase in cost associated with this will be offset by a decrease in hospital stays, along with a decrease in use of intravenous antibiotics and potentially further endoscopy. Evidence shows that performing a CT can reduce the use of subsequent endoscopy.

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Why the committee made the recommendations

For people with suspected acute diverticulitis who are not referred for urgent same-day hospital assessment, the committee agreed that watchful waiting is an option if the person is systemically well and has no comorbidities that increase the risk of infection. This decision would be in the context of shared decision making. Simple analgesia and advice can be offered. Oral antibiotics are appropriate if the person is systemically unwell but does not meet the criteria for referral with suspected complicated acute diverticulitis.

The evidence supports current practice of treating an acute episode of diverticulitis with intravenous antibiotics in secondary care. If CT confirms uncomplicated acute diverticulitis, switching to oral antibiotics does not affect outcomes. The committee recommended antibiotics for this group because they were aware of evidence that watchful waiting could increase recurrence rates and the probability of further surgery. In support of antibiotic stewardship and to avoid antibiotic resistance the committee recommended that the person should be reassessed if necessary and the need for antibiotic treatment should be reviewed.

The need for intravenous antibiotics should be reviewed, including whether to stop them, within 48 hours in line with current good practice on antibiotic prescribing or after the CT scan. The CT will confirm if the person has an abscess or not. The total course of antibiotic treatment should be for a maximum of 5 days and then reviewed. The duration may need to be longer in people with diverticular abscess. The duration of antibiotics used in the studies was variable and 5 days was based on current clinical practice and the knowledge and expertise of the committee.

In light of the lack of evidence on this topic, and the need to prevent antibiotic resistance, the committee considered this an important area for research. It made a recommendation for research on antibiotics for people with acute diverticulitis managed in primary care.

How the recommendations might affect practice

The recommendation to offer an initial treatment of intravenous antibiotics before CT scanning for confirmation reflects current practice, so there should be no change in practice. Using oral antibiotics beyond this point in place of intravenous antibiotics may reduce the resource requirement in caring for people with acute diverticulitis.

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Why the committee made the recommendations

The quality of the evidence for this topic meant that it was not possible to demonstrate greater effectiveness of one intervention over another. The results showed harms as well as benefits of treatment. The committee therefore made recommendations based on their clinical expertise and the approaches taken in the studies. The committee highlighted the risk of sepsis and agreed that it is important to refer people with suspected diverticular abscess to secondary care for same-day assessment and treatment with intravenous antibiotics in line with the NICE guideline on sepsis. The committee considered this to be standard practice.

The need for intravenous antibiotics should be reviewed within 48 hours in line with current good practice on antibiotic prescribing or after the CT scan. The CT will confirm if the person has an abscess or not.

The committee agreed that offering a CT scan to people with suspected diverticular abscess may help to determine the most appropriate treatment for each person based on the characteristics of the abscesses, such as size and location. This was based on clinical experience and the fact that most of the included studies used CT scans to confirm and assess abscesses. Non-contrast CT, MRI or ultrasound (depending on local expertise) should be offered if contrast CT is contraindicated.

The committee also decided that only abscesses greater than 3 cm should be considered for percutaneous drainage because of technical difficulties in performing this procedure on smaller abscesses. This was based on clinical expertise and was the approach taken by most of the included studies.

The committee agreed that if percutaneous drainage is an anatomically feasible option this could be considered alongside a discussion with the patient about the risks and benefits of surgery. In people with a CT-confirmed diverticular abscess, re-imaging may be considered if the condition does not improve clinically of if there is deterioration. This will guide the management strategy – for example, if further surgery is needed or if a previous collection that was not drainable percutaneously (for example because it was too small) is now drainable.

How the recommendations might affect practice

The recommendations reflect current practice.

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Why the committee made the recommendation

The committee noted that, based on the evidence, there appeared to be few differences between resection of the bowel and lavage in terms of patient outcomes. The committee agreed that for people with diverticular perforations with generalised peritonitis, both options should be discussed and a decision made based on patient preferences. A patient decision table has been developed to support this discussion.

No evidence was found for the treatment of faecal peritonitis (also known as Hinchey stage IV perforation). But the committee agreed that resection of the bowel is better than lavage because it is the only way to prevent further faecal contamination of the peritoneal cavity.This is because of the more serious nature of this condition indicated by the presence of faeces in the peritoneal cavity.

How the recommendation might affect practice

The committee considered that lavage is not commonly used in the UK for treating diverticular perforation. Implementing this recommendation may therefore require a change from current practice by the majority of providers.

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Why the committee made the recommendation

The committee agreed that there was too much uncertainty surrounding most of the evidence to recommend one intervention over the other for complicated acute diverticulitis. Very few outcomes indicated a clinical benefit of either primary anastomosis or temporary stoma. For this reason, the committee concluded that both primary anastomosis (which is a join in the bowel, with or without diverting stoma) and Hartmann's procedure should be options for people admitted to surgery for this condition. Based on the expertise and knowledge of the committee, surgeon experience, the patient's age, any other conditions the patient has and how well they can carry out everyday activities and patient condition should be considered.

In the emergency setting frail patients with multiple medical problems who have sepsis at the time of surgery may benefit from a Hartmann's procedure instead of a primary anastomosis (with or without diverting stoma) as this removes the risk of a subsequent anastomotic leak. However, the committee recognised that patients having a stoma in this setting often find these are permanent and not reversed.

How the recommendation might affect practice

The recommendation reflects current practice.

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Why the committee made the recommendation

No evidence was found on the extent of bowel resection for people with acute diverticulitis. A recommendation was developed based on the experience of the surgeons on the committee. Committee members discussed the difference between resecting back to normal bowel and resecting back to compliant bowel. The committee agreed that 'normal bowel' could be interpreted by some as bowel without diverticula, rather than bowel that is soft, unthickened and unaffected by inflammation. To avoid this confusion, resecting back to the compliant bowel, which refers to bowel that is functional and is not restricted in terms of movement, was included in the recommendation and reflects the current advice by national bodies.

How the recommendation might affect practice

The recommendation reflects current practice.

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Why the committee made the recommendation

The committee concluded that there was insufficient evidence to say whether laparoscopic resection or open resection was the better management option for people who have recovered from complicated acute diverticulitis but who have continuing symptoms.

How the recommendation might affect practice

The recommendation reflects current practice.

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Why the committee did not make any recommendations

In the studies in the evidence reviewed people were offered an intervention based on demographic and clinical characteristics. This meant it was difficult to assess the true effect of interventions on patient outcomes. Therefore the committee decided not to make any practice recommendations.

The committee thought this was an area that needed further research and therefore developed a recommendation for research on timing of surgery for complicated acute diverticulitis.

Why the committee made the recommendation

The committee noted that the evidence supported current practice of not using an aminosalicylate in managing recurrent diverticulitis. Aminosalicylates are not licensed to treat diverticulitis in the UK and there is little evidence to support their use in this area.

The committee agreed that there was insufficient evidence to support the use of antibiotics to prevent recurrent diverticular disease. In support of antibiotic stewardship and to avoid antibiotic resistance the committee recommended not offering antibiotic treatment.

How the recommendation might affect practice

The recommendation to not offer an aminosalicylate or antibiotics for the prevention of recurrent diverticulitis reflects current practice. Therefore the committee agreed there should be no change in practice.

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Why the committee made the recommendations

There was limited evidence on the support and information needed for people with diverticulosis, diverticular disease and diverticulitis and their families and carers. The evidence was from a symptom-based questionnaire and reported on the timing and success of surgery and symptoms. The committee agreed that it is important for those affected to have relevant information on these topics, but also used its knowledge and experience to expand on these topics in the recommendations.

The committee decided that given the limited evidence, this is an area that needs further research to identify the type of information people want. Therefore they made a recommendation for research on information for people with diverticulosis, diverticular disease or acute diverticulitis.

How the recommendations might affect practice

The recommendation reflects current practice.

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