29 July 2019

Rethink needed for diverticulitis

Clinical Gastro

The management of diverticulitis has changed substantially in recent years, moving towards a much more hands-off approach to less severe forms of the disease.

According to a review of international guidelines, published today in the Medical Journal of Australia, there’s been swing away from prescribing antibiotics for mild diverticulitis.

This was “a huge turn around” in thinking as antibiotics had been “the mainstay of therapy forever”, Dr Mark Muhlmann, a colorectal surgeon at Prince of Wales Hospital who was not involved in the study, said.

Nowadays, if a GP saw a patient with diverticulitis who appeared to need antibiotics, then the patient should probably be referred to a specialist, he said.

Diverticulitis is caused by infected out-pouches of the colon. And so, for a long time, antibiotics were thought to be an appropriate treatment.

But high-level evidence from meta-analyses have overturned this belief by showing that antibiotics made no difference to the course of the disease in mild, uncomplicated diverticulitis – so those cases where there are no perforations, no free gas outside the bowel wall and no sepsis, Dr Muhlmann said.

Instead of antibiotics, GPs treating mild cases of diverticulitis could prescribe a clear liquid diet, which was thought to ease abdominal pain by giving the bowel a rest, and pain-killers, Dr Muhlmann said.

“This, I guess, has benefits because the antibiotics themselves can have side-effects and also just more of a community benefit in that there is less chance of breeding resistant pathogens,” he said.

The surgical community had been very slow to accept the data, and many patients presenting to hospital with diverticulitis would still be getting antibiotics, Dr Muhlmann said.

“What has changed, however, is the feeling that it is extremely safe to manage these patients in the outpatient setting,” he said.

Some guidelines now recommended outpatient treatment for afebrile, clinically stable cases of uncomplicated diverticulitis, the MJA paper stated. The paper also confirmed that CT scan was the best way to diagnose diverticulitis, with a sensitivity and specificity of more than 94%.

“The importance of CT scan is clear,” Dr Muhlmann said.

“One of the problems in the past was that a lot of the diagnosis was made on clinical grounds.”

One of the most controversial areas of diverticulitis management has been the use of routine colonoscopy to screen for bowel cancer.

“This has been debated for as long as I can remember,” Dr Muhlmann said.

The MJA paper falls on the side of less screening, recommending colonoscopy only after a bout of complicated diverticulitis.

“There is insufficient data to support the recommendation of routine colonoscopy for uncomplicated diverticulitis; its value has been further rebuked by large studies showing that the incidence of colorectal cancers after uncomplicated diverticulitis was not different to that observed in the general population,” the authors said.

Colonoscopy did not change the management of diverticulitis in most cases, Dr Muhlmann said.

“It doesn’t help with deciding who will require surgical intervention and it doesn’t help with showing any patients that might be at higher risk of recurrence,” he said.

“So, the only reason for doing it would be to exclude a colorectal cancer.

“Although there are conflicting studies in this area and you can find arguments both ways, looking at all of the literature together, it’s probably no more common to find any colorectal cancer after an attack of diverticulitis where it is shown on CT than it would be from just picking out someone from the general population of the same age.”

MJA 2019, 29 July