Recommendations

Guidance

1.1 Diverticulosis
1.2 Diverticular disease
1.3 Acute diverticulitis
1.4 Information
Terms used in this guideline

Recommendations

People have the right to be involved in discussions and make informed decisions about their care, as described in your care. Making decisions using NICE guidelines explains how we use words to show the strength (or certainty) of our recommendations, and has information about prescribing medicines (including off-label use), professional guidelines, standards and laws (including on consent and mental capacity), and safeguarding.

People have the right to be involved in discussions and make informed decisions about their care, as described in your care.

Making decisions using NICE guidelines explains how we use words to show the strength (or certainty) of our recommendations, and has information about prescribing medicines (including off-label use), professional guidelines, standards and laws (including on consent and mental capacity), and safeguarding.

1.1 Diverticulosis

Management and advice

1.1.1 Tell people with diverticulosis that the condition is asymptomatic and no specific treatments are needed.

1.1.2 Advise people to eat a healthy, balanced diet including whole grains, fruit and vegetables. Tell them that:

there is no need to avoid seeds, nuts, popcorn or fruit skins
if they have constipation and a low-fibre diet, increasing their fibre intake gradually may minimise flatulence and bloating.

1.1.3 Advise people to drink adequate fluid if they are increasing their fibre intake, especially if there is a risk of dehydration.

1.1.4 Consider bulk-forming laxatives for people with constipation.

1.1.5 Tell people about the benefits of exercise, and weight loss if they are overweight or obese, and stopping smoking, in reducing the risk of developing acute diverticulitis and symptomatic disease.

To find out why the committee made the recommendations on diverticulosis management and advice and how they might affect practice, see rationale and impact.

1.2 Diverticular disease

Symptoms and signs

1.2.1 Suspect diverticular disease if a person presents with one or both of the following:

intermittent abdominal pain in the left lower quadrant with constipation, diarrhoea or occasional large rectal bleeds (the pain may be triggered by eating and relieved by the passage of stool or flatus)
tenderness in the left lower quadrant on abdominal examination.

Be aware that:
in a minority of people and in people of Asian origin, pain and tenderness may be localised in the right lower quadrant
symptoms may overlap with conditions such as irritable bowel syndrome, colitis and malignancy.

To find out why the committee made the recommendation on symptoms and signs of diverticular disease and how it might affect practice, see rationale and impact.

Investigations and referral

1.2.2 Do not routinely refer people with suspected diverticular disease unless:

routine endoscopic and/or radiological investigations cannot be organised from primary care or
colitis is suspected or
the person meets the criteria for a suspected cancer pathway.

1.2.3 If the person meets the criteria for a suspected cancer pathway, refer by this route (see NICE's guideline on suspected cancer: recognition and referral).

To find out why the committee made the recommendations on investigations and referral for people with suspected diverticular disease and how they might affect practice, see rationale and impact.

Management and advice

1.2.4 Do not offer antibiotics to people with diverticular disease.

1.2.5 Advise people to avoid non-steroidal anti-inflammatory drugs and opioid analgesia if possible, because they may increase the risk of diverticular perforation.

1.2.6 For advice on diet, fluid intake, stopping smoking, weight loss and exercise, follow the recommendations in section 1.1 on diverticulosis.

1.2.7 Advise people that:

the benefits of increasing dietary fibre may take several weeks to achieve
if tolerated, a high-fibre diet should be maintained for life.

1.2.8 Consider bulk-forming laxatives if:

a high-fibre diet is unacceptable to the person or it is not tolerated or
the person has persistent constipation or diarrhoea.

1.2.9 Consider simple analgesia, for example paracetamol, as needed if the person has ongoing abdominal pain.

1.2.10 Consider an antispasmodic if the person has abdominal cramping.

1.2.11 If the person has persistent symptoms or symptoms that do not respond to treatment, think about alternative causes and investigate and manage appropriately.

To find out why the committee made the recommendations on management and advice for people with diverticular disease and how they might affect practice, see rationale and impact.

Recurrent diverticular disease

The committee were unable to make recommendations for practice in this area.

For a short explanation of why the committee were unable to make recommendations on recurrent diverticular disease see rationale.

1.3 Acute diverticulitis

Symptoms and signs of acute diverticulitis

1.3.1 Suspect acute diverticulitis if a person presents with constant abdominal pain, usually severe and localising in the left lower quadrant, with any of the following:

fever or
sudden change in bowel habit and significant rectal bleeding or passage of mucus from the rectum or
tenderness in the left lower quadrant, a palpable abdominal mass or distention on abdominal examination, with a previous history of diverticulosis or diverticulitis.

Be aware that in a minority of people and in people of Asian origin, pain and tenderness may be localised in the right lower quadrant.

To find out why the committee made the recommendation on symptoms and signs of acute diverticulitis and how it might affect practice, see rationale and impact.

Symptoms and signs of complicated acute diverticulitis

1.3.2 Suspect complicated acute diverticulitis and refer for same-day hospital assessment if the person has uncontrolled abdominal pain and any of the features in table 1.

Table 1 Symptoms and signs that suggest complicated acute diverticulitis

Symptom or sign	Possible complication
Abdominal mass on examination or peri-rectal fullness on digital rectal examination	Intra-abdominal abscess
Abdominal rigidity and guarding on examination	Bowel perforation and peritonitis
Altered mental state, raised respiratory rate, low systolic blood pressure, raised heart rate, low tympanic temperature, no urine output or skin discolouration	Sepsis (see the NICE guideline on sepsis)
Faecaluria, pneumaturia, pyuria or the passage of faeces through the vagina	Fistula into the bladder or vagina
Colicky abdominal pain, absolute constipation (passage of no flatus or stool), vomiting or abdominal distention	Intestinal obstruction

To find out why the committee made the recommendation on symptoms and signs of complicated acute diverticulitis and how it might affect practice, see rationale and impact.

Investigation of suspected acute diverticulitis

Primary care

1.3.3 For people with suspected uncomplicated acute diverticulitis who are not referred for same-day hospital assessment:

reassess in primary care if their symptoms persist or worsen and
consider referral to secondary care for further assessment.

Secondary care

1.3.4 For people with suspected complicated acute diverticulitis who have been referred for same-day hospital assessment, offer a full blood count, urea and electrolytes test and C‑reactive protein test.

1.3.5 If the person with suspected complicated acute diverticulitis has raised inflammatory markers, offer a contrast CT scan within 24 hours of hospital admission to confirm diagnosis and help plan management. If contrast CT is contraindicated, perform one of the following:

a non-contrast CT or
an MRI or
an ultrasound scan, depending on local expertise.

1.3.6 If inflammatory markers are not raised, think about the possibility of alternative diagnoses.

To find out why the committee made the recommendations on investigation of suspected acute diverticulitis and how they might affect practice, see rationale and impact.

Non-surgical management of acute diverticulitis

1.3.7 For people with acute diverticulitis who are systemically well:

consider a no antibiotic prescribing strategy
offer simple analgesia, for example paracetamol
advise the person to re‑present if symptoms persist or worsen.

1.3.8 Offer an antibiotic prescribing strategy if the person with acute diverticulitis is systemically unwell, is immunosuppressed or has significant comorbidity.

1.3.9 Offer oral antibiotics if the person with acute diverticulitis is systemically unwell but does not meet the criteria for referral for suspected complicated acute diverticulitis.

1.3.10 Offer intravenous antibiotics to people admitted to secondary care with suspected complicated acute diverticulitis.

For guidance on the management of suspected sepsis see the NICE guideline on sepsis.

1.3.11 Review intravenous antibiotics within 48 hours or after scanning if sooner (see recommendation 1.3.5) and consider stepping down to oral antibiotics where possible.

1.3.12 If the person has CT-confirmed uncomplicated acute diverticulitis, review the need for antibiotics and discharge them depending on any co-existing medical conditions.

1.3.13 When prescribing an antibiotic for suspected or confirmed acute diverticulitis, follow the advice in table 2.

Table 2 Antibiotics for adults aged 18 years and over with suspected or confirmed acute diverticulitis

Antibiotic ¹	Dosage and course length ²
First-choice oral antibiotic for suspected or confirmed uncomplicated acute diverticulitis
Co‑amoxiclav	500/125 mg three times a day for 5 days
Alternative first-choice oral antibiotics if penicillin allergy or co‑amoxiclav unsuitable
Cefalexin (caution in penicillin allergy) *with* metronidazole	Cefalexin: 500 mg twice or three times a day (up to 1 to 1.5 g three or four times a day for severe infection) for 5 days Metronidazole: 400 mg three times a day for 5 days
Trimethoprim *with* metronidazole	Trimethoprim: 200 mg twice a day for 5 days Metronidazole: 400 mg three times a day for 5 days
Ciprofloxacin (only if switching from IV ciprofloxacin with specialist advice; consider safety issues³) *with* metronidazole	Ciprofloxacin: 500 mg twice a day for 5 days Metronidazole: 400 mg three times a day for 5 days
First-choice intravenous antibiotics ⁴ for suspected or confirmed complicated acute diverticulitis
Co‑amoxiclav	1.2 g three times a day
Cefuroxime *with* metronidazole	Cefuroxime: 750 mg three or four times a day (increased to 1.5 g three or four times a day if severe infection) Metronidazole: 500 mg three times a day
Amoxicillin *with* gentamicin *and* metronidazole	Amoxicillin: 500 mg three times a day (increased to 1 g four times a day if severe infection) Gentamicin: Initially 5 to 7 mg/kg once a day, subsequent doses adjusted according to serum gentamicin concentration⁵ Metronidazole: 500 mg three times a day
Ciprofloxacin⁶ (consider safety issues³) *with* metronidazole	Ciprofloxacin: 400 mg twice or three times a day Metronidazole: 500 mg three times a day
Alternative intravenous antibiotics
Consult local microbiologist
¹See BNF for appropriate use and dosing in specific populations, for example, hepatic impairment, renal impairment, pregnancy and breastfeeding, and administering intravenous (or, where appropriate, intramuscular) antibiotics. ²A longer course may be needed based on clinical assessment. Continue antibiotics for up to 14 days in people with CT‑confirmed diverticular abscess. ³See MHRA advice for restrictions and precautions for using fluoroquinolones due to very rare reports of disabling and potentially long-lasting or irreversible side effects affecting musculoskeletal and nervous systems. Warnings include: stopping treatment at first signs of a serious adverse reaction (such as tendonitis), prescribing with special caution for people over 60 years and avoiding coadministration with a corticosteroid (March 2019). ⁴Review intravenous antibiotics within 48 hours or after scanning if sooner and consider stepping down to oral antibiotics where possible. ⁵Therapeutic drug monitoring and assessment of renal function is required (BNF, August 2019). ⁶Only in people with allergy to penicillins and cephalosporins.

Emergency management of complicated acute diverticulitis

1.3.14 When prescribing an antibiotic for suspected or confirmed complicated acute diverticulitis, follow the advice in table 2.

To find out why the committee made the recommendations on the non-surgical management of acute diverticulitis and how they might affect practice, see rationale and impact.

Management of abscesses

1.3.15 For people presenting in secondary care with complicated acute diverticulitis and suspected diverticular abscess, assess and manage in line with the NICE guideline on sepsis.

1.3.16 Offer intravenous antibiotics to people with acute diverticulitis and suspected diverticular abscess.

1.3.17 When prescribing an antibiotic for diverticular abscess, follow the advice in table 2.

1.3.18 Offer a contrast CT scan to people with acute diverticulitis and suspected diverticular abscess. If contrast CT is contraindicated, perform one of the following:

a non-contrast CT or
an MRI or
an ultrasound scan, depending on local expertise.

1.3.19 Review intravenous antibiotics within 48 hours or after scanning if sooner and consider stepping down to oral antibiotics where possible.

1.3.20 Use the scan results to guide treatment based on the size and location of the abscess.

1.3.21 If a person does not have confirmed diverticular abscess, review their need for antibiotics.

1.3.22 Consider either percutaneous drainage (if anatomically feasible) or surgery (see recommendation 1.3.27) for abscesses greater than 3 cm.

1.3.23 Send samples of pus from the abscess (if it has been drained) to the microbiology laboratory to enable antibiotic treatment to be tailored to sensitivities.

1.3.24 For abscesses less than 3 cm switch to oral antibiotics where possible.

1.3.25 In people with a CT-confirmed diverticular abscess, if the condition does not improve clinically or there is deterioration, consider re-imaging to inform the management strategy.

To find out why the committee made the recommendations on the management of abscesses and how they might affect practice, see rationale and impact.

Management of bowel perforations

1.3.26 Offer either laparoscopic lavage or resectional surgery (see recommendation 1.3.27) to people with diverticular perforation with generalised peritonitis after discussing the risks and benefits of the 2 options with them (see table 3). If faecal peritonitis is identified intraoperatively, proceed to resectional surgery.

Table 3 Factors to take into account when deciding whether to have lavage or resection for diverticular perforation with generalised peritonitis

	Laparoscopic lavage	Resectional surgery
What the procedure involves	In diverticulitis this involves washing the abdominal cavity and colon using keyhole surgery.	The surgical removal of the diseased colon followed by either reattaching the remaining segments of the colon or forming an end stoma.
Effect on quality of life	There was no significant difference in quality of life scores reported for lavage and surgery.
Mortality	Although there was some benefit seen in mortality for lavage, this evidence was very uncertain.
Needing a stoma (where the bowel is connected surgically to an opening in the abdomen and stools are collected in a bag or pouch)	A stoma is not needed.	A stoma may be needed.
Pain	Less likely to relieve pain than resectional surgery.	More likely to relieve pain than lavage because the damaged bowel has been removed.
Recurrent diverticulitis	Fewer people had recurrent diverticulitis after surgery than after lavage because the diseased bowel is removed. However, the evidence was very uncertain.
Needing more operations	Evidence comparing unplanned surgery with lavage showed that fewer people needed reoperations after surgery than after lavage. Evidence that included unplanned surgery and planned surgery (scheduled stoma reversal after resectional surgery) showed that fewer people needed reoperations after lavage. However, in both cases the evidence was very uncertain.
Postoperative complications	There was no meaningful difference in the number of infections or in the need for further intervention between lavage and surgery. People who had surgery had a greater reduction in post-surgical abscesses than those who had lavage, but this evidence was of low quality.

To find out why the committee made the recommendation on the management of bowel perforations and how it might affect practice, see rationale and impact.

Anastomosis and bowel resection for people with complicated acute diverticulitis (elective and emergency surgery)

1.3.27 Offer people with complicated acute diverticulitis who are having surgery (either elective or emergency):

primary anastomosis (join in the bowel) with or without diverting stoma or
Hartmann's procedure (resection of the bowel with an end stoma).

Take into account the person's age, any other conditions they have and how well they can carry out everyday activities (WHO performance status).

To find out why the committee made the recommendation on anastomosis for people with complicated acute diverticulitis and how it might affect practice, see rationale and impact.

1.3.28 In people undergoing bowel resection, consider resecting back to the compliant bowel (that is, bowel that is soft, unthickened and unaffected by inflammation).

To find out why the committee made the recommendation on bowel resection for people with complicated acute diverticulitis and how it might affect practice, see rationale and impact.

Elective surgical management after resolution of complicated acute diverticulitis

1.3.29 Consider open or laparoscopic resection for elective surgery for people who have recovered from complicated acute diverticulitis but have continuing symptoms, for example in people with stricture or fistula.

To find out why the committee made the recommendation on elective surgical management after resolution of complicated acute diverticulitis and how it might affect practice, see rationale and impact.

Timing of surgery for complicated acute diverticulitis

The committee were unable to make recommendations for practice in this area. They made a recommendation for research.

For a short explanation of why the committee were unable to make recommendations on timing of surgery for complicated acute diverticulitis see rationale.

Management of recurrent acute diverticulitis

1.3.30 Do not offer an aminosalicylate or antibiotics to prevent recurrent acute diverticulitis.

To find out why the committee made the recommendation on the management of recurrent acute diverticulitis and how it might affect practice, see rationale and impact.

1.4 Information

Diverticulosis

1.4.1 Give people with diverticulosis, and their families and carers where appropriate, verbal and written information on:

diet and lifestyle
the course of diverticulosis and the likelihood of progression
symptoms that indicate complications or progression to diverticular disease.

Diverticular disease

1.4.2 Give people with diverticular disease, and their families and carers where appropriate, verbal and written information on:

diet and lifestyle
the course of diverticular disease and the likelihood of progression
symptoms and symptom management
when to seek medical advice.

Acute diverticulitis

1.4.3 Give people with acute diverticulitis, and their families and carers where appropriate, verbal and written information on:

diet and lifestyle
the course of acute diverticulitis and likelihood of complicated disease or recurrent episodes
symptoms
when and how to seek further medical advice
possible investigations and treatments
risks of interventions and treatments, including antibiotic resistance, and how invasive these are
role of surgery and outcomes (postoperative bowel function and symptoms).

To find out why the committee made the recommendations on information for people with diverticulosis, diverticular disease and acute diverticulitis, and how they might affect practice, see rationale and impact.

Terms used in this guideline

Acute diverticulitis

Sudden inflammation or infection associated with diverticula. Symptoms include constant abdominal pain, usually severe and localising in the left lower quadrant. Other features, including fever, may also be present.

Colitis

Inflammation of the bowel related to Crohn's disease, ulcerative colitis, ischaemia or microscopic colitis. Symptoms may include abdominal pain and change in bowel habits with passage of blood.

Complicated acute diverticulitis

The presence of complications associated with inflamed or infected diverticula. These complications may include abscess, fistula, stricture perforation and sepsis.

Diverticular disease

The presence of diverticula with mild abdominal pain or tenderness and no systemic symptoms.

Diverticulosis

The presence of diverticula without symptoms.