Refer for surgical evaluation in cases of complicated acute diverticulitis, such as when there is an intra-abdominal abscess, bowel perforation, peritonitis, fistula formation, or intestinal obstruction, which require urgent surgical intervention NICE NG147.
Consider referral if the patient has persistent or recurrent episodes of diverticulitis, especially if episodes are severe or frequent, or if there are complications such as stricture or fistula formation NICE CKS.
Patients who are immunocompromised or have significant comorbidities at high risk of complications may also require surgical assessment NICE NG147.
Additionally, if the patient does not improve with medical treatment or presents with features suggestive of complicated diverticulitis, they should be referred for surgical evaluation NICE NG147.