- Explore Our Forums And Connect With Other People Living With Diverticulitis
- Diverticular Disease and Diverticulitis FAQ’s
- What Is The Difference Between Diverticulosis And Diverticulitis?
- What Are Diverticula?
- What Is Diverticulitis?
- What Is Diverticulosis?
- Diverticulitis Diagnosis
- Diverticulitis Symptoms
- What Is A Diverticulitis Flare-Up?
- Diverticulitis Treatment
- Diverticulitis Surgery
- When To Go To Hospital With Diverticulitis
- Diverticulitis Diet And Pain Free Foods
- What Is A Diverticulitis Diet?
- Diverticulitis Causes
- Is Diverticulitis Hereditary?
- Diverticulitis Pain
- Diverticulitis Complications
- Other Forms Of Diverticulitis – Bladder Diverticula
- Meckel’s Diverticulitis
- What About Diverticulitis Of The Oesophagus?
- Diverticulitis Prevention
- Diverticulitis Research Funding
- Diverticulitis Patient Stories
- Explore Our Forums
- Stop Guessing. Start Understanding
Disclaimer: This guide does not constitute medical advice. Always seek advice from a qualified medical practitioner about your own symptoms, diagnosis or treatment. This guide draws on NHS guidance alongside anonymised insights from discussions within our Diverticulitis Club Facebook group.
Welcome to the Ultimate Guide to Diverticulosis and Diverticulitis. Whether you’ve just been diagnosed or you’re seeking detailed information, you’ve come to the right place. This guide, and our entire website, offers a wealth of knowledge, practical tips, and insights from others living with diverticulitis as well as practical tools such as our food and symptoms diary tracker. Our goal is to help you understand how to live with diverticulosis and manage diverticulitis. Use our links for deeper insights and join our forums to connect with others.
In this guide, we’ll cover common questions about symptoms, treatment, causes, pain, prevention, and diagnosis. We’ll address misconceptions and provide practical advice for managing these conditions. Whether you’re newly diagnosed, a concerned family member, or someone curious for more knowledge, we’ve got you covered.
“I’d never even heard of diverticulitis! Talking to doctors was fine but being part of the Diverticulitis Club has helped me to understand how to live with it day-to-day.” – Liz, Boston, 57
Explore Our Forums And Connect With Other People Living With Diverticulitis
Remember, knowledge is power. By equipping yourself with the right information, you can take control of your health and improve your well-being. A good place to start is with some frequently asked questions.
Diverticular Disease and Diverticulitis FAQ’s
Diverticular disease is the term doctors use to describe diverticulosis and diverticulitis together, and it’s one of the most common conditions affecting the large intestine in adults over 50. The NHS explains that diverticular disease and diverticulitis cause tummy pain and other symptoms, and both are caused by small bulges or pouches, known as diverticula, that form in the wall of the intestine. Bowel Research UK estimates that around half of people aged over 50 develop diverticulae in their colon, rising to around 70% by the age of 80, although most people never know they have them and experience no symptoms at all.
NEW The table below sets out the difference between the four terms members most often ask us about.
Term | What It Means |
Diverticula | Small pouches that bulge out through weak spots in the wall of the colon |
Diverticulosis | The presence of diverticula with no symptoms |
Diverticular Disease | Diverticula that are causing symptoms, such as pain or bloating |
Diverticulitis | Diverticula that have become inflamed or infected |
NEW “I got my results back and the letter said diverticular disease. I thought I had diverticulitis and spent a whole weekend worrying before my GP explained they’re not the same thing.” – Sandra, Preston, 63
What Is The Difference Between Diverticulosis And Diverticulitis?
Diverticulosis refers to the presence of small, bulging pouches called diverticula that form in the lining of the colon, especially in the sigmoid colon. These pouches develop when weak spots in the colon wall allow the inner layer to push through. Diverticulosis is common, particularly among older adults, and often causes no symptoms. It’s often discovered during routine investigations.
Diverticulitis, however, occurs when these pouches become inflamed or infected. This can happen when bacteria are trapped in the diverticula, leading to infection. Symptoms include abdominal pain (usually in the lower left side), fever, nausea, vomiting, changes in bowel habits, and sometimes rectal bleeding. Diverticulitis can vary from mild to severe, with potential complications like abscesses, perforation of the colon, or fistulas. Read more about the difference between diverticulitis and diverticulosis with insight from our members.
A side-by-side comparison makes the practical difference clearer:
Feature | Diverticulosis | Diverticulitis |
Symptoms | Usually none | Pain, fever, changes in bowel habit |
Cause | Ageing and low fibre intake | Infection or inflammation of diverticula |
How It Is Found | Often by chance, e.g. colonoscopy | Usually diagnosed after symptoms appear, confirmed by CT scan |
Typical Treatment | Diet and lifestyle changes | Rest, fluids, sometimes antibiotics or surgery |
Urgency | Not urgent | Ranges from manageable at home to a medical emergency |
“My colonoscopy showed diverticulosis and the nurse said most people my age have it. It wasn’t until three years later, when I ended up in A&E with a fever, that I understood what diverticulitis actually felt like.” – David, Cardiff, 59
What Are Diverticula?
Diverticula develop gradually over many years as pressure inside the colon pushes the inner lining through naturally weaker areas of the bowel wall. They most often form in the sigmoid colon, the lower left section of the large intestine, because this part of the bowel experiences some of the highest pressures as it moves stool towards the rectum.
Most people develop several diverticula rather than just one, and the number often increases with age. In many cases they never cause symptoms and are only discovered during investigations for an unrelated problem.
Although diverticula themselves are usually harmless, they become important if one or more become inflamed or infected, leading to diverticulitis. Their location in the sigmoid colon is also one reason pain from diverticulitis is most commonly felt in the lower left side of the abdomen, although some people experience pain elsewhere.
Research suggests that ageing, diet, genetics and lifestyle all influence whether diverticula develop, which helps explain why some people have only a few pouches while others develop many.
What Is Diverticulitis?
Diverticulitis develops when one or more diverticula become inflamed or infected. Although many people have diverticulosis for years without symptoms, diverticulitis causes the pain, fever and digestive symptoms most people associate with the condition. Explore the causes of diverticulitis.
Diverticulitis ICD-10 Codes
Diverticulitis is recorded using ICD-10 codes, which doctors, hospitals and insurers use to log a diagnosis consistently. These codes sit within the K57 category for diverticular disease of the intestine. They’re a clinical and administrative tool rather than something you need to interpret yourself, but understanding them can help you make sense of hospital letters, discharge summaries or insurance paperwork.
Code | What It Means |
K57.30 | Diverticulosis of the large intestine, no perforation, abscess or bleeding |
K57.32 | Diverticulitis of the large intestine, no perforation or abscess, no bleeding |
K57.33 | Diverticulitis of the large intestine, no perforation or abscess, with bleeding |
K57.20 | Diverticulitis of the large intestine with perforation and abscess, no bleeding |
K57.21 | Diverticulitis of the large intestine with perforation and abscess, with bleeding |
These are the codes most commonly used for colonic diverticulitis. The exact code a doctor uses depends on which part of the bowel is affected and whether there are complications such as bleeding, an abscess or a perforation. This is background information only; it does not replace a formal diagnosis from a doctor.
What Is Diverticulosis?
Diverticulosis is a condition where small pouches called diverticula form in the lining of the colon. It’s most common in individuals over 40 and often goes unnoticed because it usually doesn’t cause symptoms. It’s often discovered incidentally during routine exams like a colonoscopy. Managing diverticulosis typically involves lifestyle changes to prevent complications, including a high-fibre diet, plenty of fluids, and regular exercise.
Diverticulitis Diagnosis
Diagnosing diverticulitis involves evaluating medical history, conducting physical exams, and performing diagnostic tests such as blood tests and imaging studies. A doctor will assess symptoms, check for tenderness or swelling, and may order blood tests to look for signs of infection or inflammation. Imaging tests like a CT scan, ultrasound, or X-ray can help identify inflamed or infected diverticula.
A CT scan is generally the most reliable way to confirm diverticulitis and check for complications such as an abscess. The NHS notes that a colonoscopy or flexible sigmoidoscopy may also be used, usually once the acute infection has settled down.
Diverticulitis Symptoms
- Diverticulitis symptoms vary but often include:
- Abdominal pain, usually on the lower left side.
- Tenderness in the affected area.
- Fever.
- Changes in bowel habits, such as constipation or diarrhoea.
- Nausea and vomiting.
- Bloating and gas.
- Rectal bleeding in some cases.
Symptoms do not always appear the same way twice, even in the same person. Some members describe a flare-up building gradually over a few days, while others say it comes on within hours.
“My first flare felt like a dull ache that got worse after eating. My second one hit hard overnight with a temperature and I couldn’t stand up straight. I’ve learned not to assume it will feel the same each time.” – Angela, Truro, 66
What Is A Diverticulitis Flare-Up?
A diverticulitis flare-up is a period when the diverticula become inflamed or infected and symptoms return or worsen. Between flare-ups, many people have no symptoms at all or only mild discomfort from diverticulosis or diverticular disease.
No two flare-ups are exactly alike. Some begin with a dull ache that gradually becomes more painful over a day or two, while others develop suddenly within a few hours. A flare-up can last anywhere from a few days to several weeks, depending on its severity, how quickly treatment begins and whether complications develop.
Having one flare-up does not necessarily mean you’ll have another, but previous diverticulitis does increase the risk of future episodes. Many people experience only a single attack during their lifetime, while others have recurring flare-ups separated by months or even years.
If your pain is becoming more severe, you’re unable to keep fluids down, develop a high temperature, or notice heavy rectal bleeding, seek urgent medical advice rather than trying to manage the symptoms at home. Learn more about how long a diverticulitis flare-up typically lasts.
Diverticulitis Treatment
Treatment goals include relieving symptoms, resolving active diverticulitis, and preventing complications. Treatments vary based on severity:
- Mild cases: Treated with antibiotics, a clear liquid diet, and over-the-counter pain relievers.
- Severe cases: May require hospitalisation, intravenous antibiotics, bowel rest, and possibly surgery if complications arise.
Mild diverticulitis is not always treated with antibiotics. Current guidance recognises that some straightforward cases settle with rest, a temporary change in diet and simple pain relief alone, and a GP will decide what’s appropriate based on symptoms and any signs of infection. Paracetamol is generally preferred over anti-inflammatory painkillers such as ibuprofen, as the NHS advises that NSAIDs and opioid painkillers can increase the risk of complications such as a perforation. Read more about medication options for diverticulitis.
“I was convinced I needed antibiotics every time, but my GP explained that mild flares often settle with rest and fluids alone. It took some getting used to, but she was right.” – Patricia, Swansea, 68
Diverticulitis Surgery
Surgery is not the first step for most people with diverticulitis. It’s generally reserved for repeated severe flare-ups, complications such as an abscess or perforation, or cases that do not respond to antibiotics. Depending on what’s found, surgery might involve draining an abscess or removing the affected section of bowel. Some people need a temporary or permanent colostomy, where the bowel is brought out through an opening in the abdomen and waste is collected in a bag. This tends to worry members more than almost anything else about their diagnosis, but it applies to a small minority of cases. Discover more about diverticulitis treatment options.
“The word colostomy terrified me before my surgery. Afterwards, one of the ladies in the group who’d already had one talked me through what daily life was actually like, and it helped more than any leaflet did.” – Barbara, Aberdeen, 71
When To Go To Hospital With Diverticulitis
Knowing when to seek help quickly matters, because diverticulitis can occasionally become serious. The NHS advises getting an urgent GP appointment or contacting NHS 111 if you notice blood or mucus in your stool, tummy pain that’s getting worse or won’t go away, a high temperature or feeling hot, cold or shivery, being unable to keep fluids down, or diarrhoea lasting more than seven days.
Call 999 or go to A&E immediately if you or someone you’re with:
- Has severe tummy pain along with vomiting, a swollen tummy, or an inability to pass stool or wind
- Is bleeding heavily from the bottom
- Seems confused, has pale or blotchy skin, a very high or low temperature, or is breathing rapidly, as these can be signs of sepsis
“I kept telling myself it was just a bad stomach ache and I’d tough it out. By the time I got to A&E I had a perforation. Now I tell anyone who’ll listen not to wait it out at home if the pain keeps getting worse.” – Michael, Belfast, 64
Diverticulitis Diet And Pain Free Foods
Managing diverticulitis includes adopting a balanced diet to promote regular bowel movements and reduce inflammation. Recommendations include:
- High-fibre foods: Fruits, vegetables, whole grains, and legumes.
- Soft, easily digestible foods during flare-ups: Cooked vegetables, lean proteins, low-fat dairy, smoothies, and soups.
- Staying hydrated.
- Avoiding trigger foods like spicy foods, high-fat meats, refined sugars, carbonated beverages, and alcohol.
During an acute flare-up, many people are advised to follow a short clear liquid diet, sticking to water, clear broth, ice lollies and weak squash, before gradually reintroducing low-fibre foods and building back up to a normal high-fibre diet as symptoms ease. The NHS notes there are no specific foods that everyone with diverticular disease needs to avoid, and that fibre should be increased slowly rather than all at once. See what our members say about whether food actually triggers diverticulitis, including eating salad and ice cream during recovery.
Often Easier During A Flare | Can Be Trickier For Some |
Clear broths and soups | Nuts, seeds and popcorn (though current NHS guidance no longer says these must be routinely avoided) |
Plain rice, pasta and toast | Spicy or very fatty food |
Cooked, skinless vegetables | Raw, high-fibre salad vegetables |
Smoothies without seeds or skins | Carbonated or alcoholic drinks |
Lean, well-cooked protein | Red or processed meat in large quantities |
“I was scared of nuts and seeds for years because that’s what I’d always heard. My dietitian told me the advice had moved on and there was no need to avoid them once I was well, which felt like a weight off.” – Janet, Dundee, 58
“I don’t get symptoms from a single glass of wine, but two or three in an evening reliably gives me trouble the next day. It’s taught me that quantity matters more than I expected.” – Colin, Exeter, 60
What Is A Diverticulitis Diet?
There isn’t one single diverticulitis diet. During an acute flare-up your doctor may recommend a temporary low residue or clear liquid diet before gradually returning to normal eating. Between flare-ups, NHS guidance focuses on increasing fibre gradually, staying hydrated and identifying any foods that consistently trigger symptoms for you personally.
Diverticulitis Causes
Diverticulitis occurs when diverticula in the colon become inflamed or infected. Factors include a low-fibre diet, increased colon pressure, age, genetic predisposition, lack of physical activity, and smoking. Not everyone with diverticula will develop diverticulitis, but lifestyle adjustments can help manage and reduce risks.
Is Diverticulitis Hereditary?
Genetics appear to play a part in who develops diverticulitis, and having a close relative with the condition may increase your own risk, though diet, age and lifestyle remain significant factors too. Diverticulitis is not considered directly inherited in the way some conditions are, but researchers continue to study a family tendency towards it.
“My mother had diverticulitis, my aunt had it, and now I do too. My GP said there’s likely a genetic thread running through my family, alongside the diet we all grew up on.” – Helen, York, 55
Diverticulitis Pain
Pain from diverticulitis varies but often includes lower left abdominal pain. Severity can range from mild discomfort to severe, sharp pains. The pain can be constant or intermittent and may worsen with inflammation or infection.
A small number of people feel their pain on the right side rather than the left, which can lead to confusion with conditions such as appendicitis before diverticulitis is confirmed.
“My pain was on the right side, so the first doctor I saw thought it might be my appendix. It took a CT scan to confirm it was diverticulitis instead.” – Susan, Plymouth, 62
Diverticulitis Complications
While most cases are manageable, complications can include abscesses, fistulas, perforation, and peritonitis. Prompt medical intervention is crucial to prevent and manage these complications.
An abscess develops when pus collects around an area of infected diverticula, and a perforation is a hole that forms in the bowel wall, both usually identified on a CT scan. Left untreated, a perforation can lead to peritonitis, a serious infection of the abdominal lining that needs emergency treatment. These complications are relatively rare, but they’re the reason doctors take persistent or worsening symptoms seriously rather than waiting to see if things settle on their own.
Other Forms Of Diverticulitis – Bladder Diverticula
Bladder diverticula are pouches that form in the bladder wall due to weak spots. They can be congenital or acquired and may cause symptoms like frequent urination, urgency, incomplete bladder emptying, UTIs, or bladder stones. Treatment depends on size and symptoms, ranging from monitoring to surgery.
Meckel’s Diverticulitis
Meckel’s diverticulum is a congenital pouch in the small intestine that can cause complications like Meckel’s diverticulitis, characterised by inflammation or infection. Symptoms include abdominal pain and gastrointestinal bleeding. Treatment usually involves surgical removal of the diverticulum.
What About Diverticulitis Of The Oesophagus?
Diverticula can occasionally form in the oesophagus, though this is a separate condition to colonic diverticulitis and is far less common. Oesophageal diverticula, sometimes called a Zenker’s diverticulum when they occur near the throat, tend to cause difficulty swallowing, regurgitation or bad breath rather than the abdominal symptoms associated with colonic diverticulitis. If you’re researching symptoms in this area, it’s worth mentioning this specifically to your doctor, since the causes and treatment differ from the colonic diverticulitis covered throughout most of this guide.
Diverticulitis Prevention
Preventive measures include a high-fibre diet, adequate hydration, regular exercise, avoiding straining during bowel movements, limiting processed foods and red meat, managing stress, and maintaining regular bowel habits. These steps can help reduce the risk of developing diverticulitis or managing its symptoms.
Diverticulitis Research Funding
Research funding for diverticulitis has increased but remains relatively underfunded. Factors driving research include the rising incidence of the condition, understanding its causes, developing new treatments, and preventing complications. Research areas include the role of diet, microbiome, new treatment strategies, diagnostic tools, and long-term complications.
Diverticulitis Patient Stories
Explore Our Forums
Our forums offer a safe space to discuss all aspects of diverticulitis, from diet and pain management to personal experiences. Join the conversation, share recipes, and learn coping strategies from others.
Disclaimer: This guide does not constitute medical advice. If you’re worried about your symptoms, please contact your GP or NHS 111, or call 999 in an emergency. Always seek advice from a qualified medical practitioner about your own diagnosis and treatment.
