Investigation of suspected acute diverticulitis
Primary care
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)
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.
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
If inflammatory markers are not raised, think about the possibility of alternative diagnoses.
A review suggests (2):
- in patients presenting with suspected acute diverticulitis
- an abdominal computed tomography scan should be performed to confirm the diagnosis, to determine the severity of disease, and to rule out an alternative diagnosis
- is most important for the first presentation and less important for a stereotypical mild recurrence
- in centers with expertise in ultrasonography
- a step-up approach with computed tomography performed after an inconclusive or negative ultrasound scan may be considered
- computed tomography
- performs better in obese patients and is better able to assess the distal sigmoid colon, which is difficult to visualize with transabdominal ultrasonography
- colonoscopy
- should be performed six to eight weeks after a diagnosis of complicated diverticulitis or first episode of uncomplicated diverticulitis
- in the absence of alarm symptoms, a colonoscopy does not need to be repeated if a high quality examination has been performed in the previous year
- patients with recurrent uncomplicated diverticulitis and no alarm symptoms should follow routine colorectal cancer screening and surveillance intervals
- ongoing gastrointestinal symptoms
- common after recovery from the acute phase of diverticulitis, and alternative diagnoses should be considered
- repeat imaging and colonoscopy is often necessary to rule out a misdiagnosis or ongoing inflammation
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