Treatment options for diverticular disease and diverticulitis depend on how severe your symptoms are.

Diverticular disease

Most cases of diverticular disease can be treated at home. The over-the-counter painkiller paracetamol is recommended to help relieve your symptoms. Painkillers known as non-steroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen, are not recommended because they may upset your stomach and increase your risk of internal bleeding.

Eating a high-fibre diet may initially help to control your symptoms. Some people will notice an improvement after a few days, although it can take around a month to feel the benefits fully. If you have constipation, you may be given a bulk-forming laxative. These can cause flatulence (wind) and bloating. Drink plenty of fluids to prevent any obstruction in your digestive system.

Heavy or constant rectal bleeding occurs in about 1 in 20 cases of diverticular disease. This can happen if the blood vessels in your large intestine (colon) are weakened by the diverticula, making them vulnerable to damage. The bleeding is usually painless, but losing too much blood can be potentially serious and may need a blood transfusion.

Treatment at home

Mild diverticulitis can often be treated at home. Your GP will prescribe antibiotics for the infection and you should take paracetamol for the pain. It's important that you finish the complete course of antibiotics, even if you are feeling better. Some types of antibiotics used to treat diverticulitis can cause side effects in some people, including vomiting and diarrhoea. 

Your GP may recommend that you stick to a fluid-only diet for a few days until your symptoms improve. This is because trying to digest solid foods may make your symptoms worse. You can gradually introduce solid foods over the next 2 or 3 days.

For the 3 to 4 days of recovery, a low-fibre diet is suggested, until you return to the preventative high-fibre diet. This is to reduce the amount of faeces (poo) your large bowel has to deal with while it is inflamed.

If you have not been diagnosed with diverticular disease before, your GP may refer you for a test such as a colonoscopy or CT colonography after the symptoms have settled.

Treatment at hospital

If you have more severe diverticulitis, you may need to go to hospital, particularly if:

• your pain cannot be controlled using paracetamol
• you are unable to drink enough fluids to keep yourself hydrated
• you are unable to take antibiotics by mouth 
• your general state of health is poor
• you have a weakened immune system
• your GP suspects complications
• your symptoms fail to improve after two days of treatment at home

If you are admitted to hospital for treatment, you are likely to receive injections of antibiotics and be kept hydrated and nourished using an intravenous drip (a tube directly connected to your vein). Most people start to improve within 2 to 3 days.

Surgery

In the past, surgery was recommended as a preventative measure for people who had 2 episodes of diverticulitis as a precaution to prevent complications. This is no longer the case, as studies have found that in most cases, risks of serious complications from surgery (estimated to be around 1 in 100) usually outweigh the benefits.

If surgery is being considered, discuss both benefits and risks carefully with the doctor in charge of your care. In rare cases, a severe episode of diverticulitis can only be treated with emergency surgery. This is when a hole (perforation) has developed in the bowel. This is uncommon, but causes very severe abdominal pain, which needs an emergency trip to hospital.

Colectomy

Surgery for diverticulitis involves removing the affected section of your large intestine. This is known as a colectomy. Emergency surgery when the bowel has perforated is more likely to be open and may result in a stoma being formed.

Stoma surgery ('having a bag')

In some cases, the surgeon may decide your large intestine needs to heal before it can be reattached, or that too much of your large intestine has been removed to make reattachment possible.

In such cases, stoma surgery provides a way of removing waste materials from your body without using all of your large intestine. It is known as "having a bag" as a bag is stuck to the skin on your belly and the faeces (poo) are collected in the bag.

In most cases, the stoma will be temporary and can be removed once your large intestine has recovered from the surgery. This will depend on the situation when you had the operation. If it was an emergency operation, you may need a few months to recover before having surgery to reverse the stoma.

Results of surgery

In general terms, elective (non-emergency) surgery is usually successful, although it does not achieve a complete cure in all cases. Following surgery, an estimated 1 in 12 people will have a recurrence of symptoms of diverticular disease and diverticulitis. 

In an emergency setting, the success rate depends on how unwell you are when you require the operation.