Diverticula (mucosal outpouching through the wall of the colon) are rare before the age of 40 years, after which prevalence increases steadily and reaches over 25% by 60 years. However, only 10% to 25% of affected people will develop symptoms such as lower abdominal pain. Recurrent symptoms are common, and 5% of people with diverticula eventually develop complications such as perforation, obstruction, haemorrhage, fistulae, or abscesses.We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of: treatments for uncomplicated diverticular disease; treatments to prevent complications; and treatments for acute diverticulitis? We searched: Medline, Embase, The Cochrane Library, and other important databases up to May 2010 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).We found 16 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.In this systematic review we present information relating to the effectiveness and safety of the following interventions: antispasmodics, elective surgery, increasing fibre intake with bran or ispaghula husk, lactulose, medical treatment, mesalazine, methylcellulose, rifaximin, and surgery.