Diverticulitis: symptoms, treatment, diet and recovery

The NHS says that if the bowel becomes infected or inflamed, it is called diverticulitis, and symptoms include severe, constant tummy pain, a high temperature, and bleeding or passing slime (mucus) from your bottom. NHS inform says the pain is constant and severe rather than stop-start, develops over a day or 2, and usually starts below the belly button before moving to the lower left side. In Asian people it may move to the lower right side.

NHS inform adds a fever of 38C or above, a general feeling of being tired and unwell, and feeling or being sick. The NHS notes that symptoms are similar to those of other conditions such as irritable bowel syndrome.

The NHS says diverticulitis is treated with antibiotics if it is caused by an infection, and painkillers such as paracetamol. NHS inform says mild diverticulitis can usually be treated at home with antibiotics prescribed by your GP, while more serious cases may need hospital treatment, and surgery is sometimes recommended if there have been serious complications, though this is rare.

NICE Clinical Knowledge Summaries advises that for suspected uncomplicated diverticulitis in primary care, an oral antibiotic is offered if the person is systemically unwell, immunosuppressed or has significant other conditions, and that a no-antibiotic approach can be considered for people who are systemically well. Referral to a colorectal surgeon may be considered for frequent or severe recurrent episodes.

The NHS says that to reduce the risk of symptoms worsening in future, eat a healthy, balanced diet including whole grains, fruit and vegetables, slowly increase fibre if you do not eat much, drink plenty of water, stop smoking and maintain a healthy weight. It says there are no specific foods you need to avoid.

NHS inform describes the diet during an acute attack in more detail: a low-fibre diet for the 3 to 4 days of recovery, with solid foods introduced gradually over 2 or 3 days if you have been on fluids, until you return to the preventative high-fibre diet. It also says that if you have established diverticular disease it may be suggested to avoid nuts, corn and seeds, which differs from the NHS statement, so ask your GP what applies to you.

NHS inform says it is recommended to increase fibre gradually over a few weeks to avoid bloating and wind, and that people aged 50 to 70 who eat a high-fibre diet (25g a day) have a 40% lower chance of admission to hospital with complications of diverticular disease than others with the lowest fibre intake.

NICE Clinical Knowledge Summaries describes three states. Diverticulosis is when diverticula are present without symptoms. Diverticular disease is when diverticula cause symptoms such as intermittent lower abdominal pain, without inflammation and infection. Diverticulitis is when diverticula become inflamed and infected, typically causing severe lower abdominal pain, fever, malaise, a change in bowel habit and occasionally rectal bleeding.

NHS inform says the exact reason diverticula develop is not known, but they are associated with not eating enough fibre. There is no clinical evidence to fully prove the link, but diverticular disease is much more common in Western countries, where many people do not eat enough fibre. Diverticulitis is caused by an infection of one or more of the diverticula.

NHS inform lists factors that appear to increase the risk of diverticular disease: smoking, being overweight or obese, a history of constipation, use of NSAID painkillers such as ibuprofen or naproxen, and having a close relative with diverticular disease. NICE Clinical Knowledge Summaries says diverticula are rare before 40 and risk increases with age.

The NHS says a GP will ask questions to find out what is causing your symptoms, and you may need a blood test or a poo sample. Further tests may include a colonoscopy or flexible sigmoidoscopy, where a thin tube with a camera checks inside the bowel, or a CT scan, to confirm the diagnosis and rule out other conditions.

NHS inform says that if symptoms are mild your GP will treat it at home, and if you have not had diverticular disease diagnosed before your GP may refer you for a colonoscopy or CT colonography after the symptoms have settled.

NHS inform says that if symptoms are mild and your GP treats it at home, you should recover within 4 days, followed by a few days of low-fibre diet before returning to a high-fibre diet. The NHS pages read do not give a longer timescale, so if symptoms are not improving, speak to your GP or NHS 111.

The NHS says to ask for an urgent GP appointment or get help from NHS 111 if tummy pain is getting worse or does not go away, you have a high temperature or feel hot, cold or shivery, you have blood or slime in your poo, you keep being sick and cannot keep fluid down, or you have diarrhoea for more than 7 days or are being sick for more than 2 days.

The NHS says that, rarely, diverticulitis can lead to an abscess (a build-up of pus) in the bowel, a blockage, a fistula (an opening between the bowel and another organ such as the bladder) or a hole (perforation) in the bowel, which can cause a severe infection called peritonitis. These can sometimes be treated with antibiotics or surgery, and some people need a colostomy.

Call 999 or go to A&E, according to the NHS, if you or someone you care for has severe tummy pain and is either vomiting, has a swollen tummy or cannot poo or fart, is bleeding heavily from the bottom, or is confused, has pale or blotchy skin, a very high or low temperature, or is breathless or breathing rapidly, which could be signs of sepsis.

On the NHS the usual route is a GP or NHS 111 assessment, with hospital admission for complicated cases. Diagnostic tests such as colonoscopy or CT may be arranged afterwards. Private gastroenterology or colorectal surgical appointments and imaging are available to people who choose to pay or have insurance, for example for follow-up investigation or discussion of surgery for recurrent attacks. NICE Clinical Knowledge Summaries lists frequent or severe recurrent episodes as a reason for colorectal surgical referral.