Disclaimer: This article does not constitute medical advice. Always seek advice from a qualified medical practitioner about your own symptoms, diagnosis or treatment.
- How Does Diverticulitis Pain Differ From Everyday Diverticular Disease?
- Which Symptoms Do Doctors Use To Suspect Diverticulitis?
- Does Diverticulitis Always Cause A Fever?
- How Do Members Tell Diverticulitis From IBS?
- What Did Members’ Doctors Suspect First?
- Does Age Change How Doctors Read The Pain?
- Which Tests Confirm Diverticulitis?
- Why Do Some Members Find Out Years Later?
- How Do Members Decide Between Waiting And Seeking Help?
- How Can A Symptom Diary Help You Describe Your Pain?
- Frequently Asked Questions
- Can I Diagnose Diverticulitis Myself?
- Is Diverticulitis Pain Constant Or Does It Come And Go?
- Can A Blood Test Show Diverticulitis?
- Why Did A Scan Mention Diverticulitis When Nobody Told Me?
- Can Diverticulitis Cause Weight Loss?
- Key Takeaways
- Sources And Further Reading
- Stop Guessing. Start Understanding
This article is based on anonymised discussions from our Diverticulitis Club group on Facebook, set alongside guidance from the NHS, NICE, BMJ Best Practice and published clinical research. We change member names and locations.
You cannot diagnose diverticulitis from pain alone. Constant, severe pain in the lower left abdomen that builds over a day or two, alongside a fever or a change in bowel habit, fits the pattern, but a doctor confirms the diagnosis with blood tests and, in most cases, a CT scan. NICE’s evidence review found that the symptoms of diverticular disease are not specific enough to diagnose it, because bowel cancer, inflammatory bowel disease, irritable bowel syndrome and, in women, ovarian and other gynaecological conditions produce similar symptoms.
Our members know this confusion from both sides. Some spend days unsure whether their pain justifies a phone call. Others learn from an old scan report that they have had diverticular changes for years, and nobody told them. This article explains what separates diverticulitis pain from other pain, which tests settle the question, and what members wish they had known sooner.
How Does Diverticulitis Pain Differ From Everyday Diverticular Disease?
NHS Inform guidance separates two situations that members often blur together, and NI Direct publishes similar guidance. Diverticular disease causes intermittent, stop-start pain in the lower abdomen, usually on the left. Diverticulitis shares most of those symptoms, but the pain turns constant and severe and develops over a day or two. The guidance tells people who suspect diverticulitis to contact a GP as soon as possible, while people with an existing diagnosis of diverticular disease usually manage their symptoms at home.
Feature | Diverticular Disease | Diverticulitis |
Pain pattern | Intermittent, stop-start | Constant and severe |
Speed of onset | Comes and goes over months or years | Develops over a day or two |
Usual location | Lower abdomen, usually the left | Lower abdomen, usually the left |
Fever | Not listed among the symptoms | A high temperature, with raised inflammation markers in blood tests |
Guidance on seeking help | Previously diagnosed: usually managed at home | Contact a GP as soon as possible |
Sources: NHS Inform; NI Direct; NHS; BMJ Best Practice.
“If you’ve had a diverticulitis episode before, you’ll probably recognise it the next time. If you haven’t, it can be easily confused with other things.”
Mark, UK
Experience of previous flares changes how reliably you can read your own pain. Margery from Whitby describes the learning curve:
“Everyone is different. I’d say if in doubt seek help, especially if in severe pain or fever. In time you will learn how your body works with this illness.”
Margery from Whitby
First-timers carry the heaviest uncertainty, because nothing in their history tells them which kind of pain they feel. Our guide to what diverticulitis pain feels like describes the sensation in detail, and our article on the first signs of a flare covers where it starts.
Which Symptoms Do Doctors Use To Suspect Diverticulitis?
Clinical guidance weighs each clue separately, and the weighting surprises many members. The table below sets out what BMJ Best Practice, NICE and NHS Inform say about each one.
Clue | What The Evidence Says | Source |
Lower left abdominal pain | A key diagnostic factor. NICE’s expert panel agreed that most people feel pain on the left, where diverticula most often form. | BMJ; NICE |
Fever | A key diagnostic factor for acute diverticulitis. | BMJ |
Raised white blood cell count | A key diagnostic factor, found through blood tests. | BMJ |
Tenderness or guarding in the lower left abdomen | Found on examination and listed as a supporting factor. | BMJ |
Bloating | BMJ lists it as a supporting factor. NICE’s panel removed a bloating statement because respondents judged it non-specific. | BMJ; NICE |
Constipation or diarrhoea | NICE describes a change in bowel habit towards constipation or looser stools as typical. In one study of 1,629 people, constipation, diarrhoea, loose stool and hard stool were not clinically important predictors of diverticulosis (very low quality evidence). | NICE |
Mucus passed from the back passage | NICE’s panel removed this statement, because respondents linked it more to irritable bowel disorder or inflammatory disease. | NICE |
Weight loss | Diverticular disease does not cause weight loss. NHS Inform advises seeing a GP if you lose weight, see blood in your stools or have frequent bowel changes. | NHS Inform |
Members often list bloating and bowel changes first when they describe a flare. The evidence ranks them below pain, fever and blood results, and no single clue separates diverticulitis from its look-alikes. Doctors combine the pattern with tests.
Does Diverticulitis Always Cause A Fever?
No, according to members. BMJ Best Practice lists fever as a key diagnostic factor, and several members repeat what their doctors told them about temperature.
“My doctor told me that a high temperature is a sign of infection.”
Heather from Wrexham
Five members in the discussion described a different experience: significant illness without a fever, including hospital admissions for sepsis or a very high white blood cell count.
“I get infections without a fever. I even had sepsis without a temperature. I think it’s usual to get one, but everyone is different, so we can’t assume there’s no infection because there’s no fever.”
Joan from Leicester
“I didn’t get a fever but was hospitalised for a very high white blood count with my diverticulitis.”
Ruth from Ayr
BMJ Best Practice lists a raised white cell count alongside fever as a key diagnostic factor, which gives doctors a second marker when a thermometer reads normal. A case report on diverticulitis in a young adult adds that a fever of 38 °C or above on admission predicts a higher risk of complications in people under 40. A fever adds weight to the concern. A normal temperature does not settle it, and members who have been through flares say they learned this the hard way.
How Do Members Tell Diverticulitis From IBS?
Irritable bowel syndrome produced the most questions in the discussion, and one finding surprised several members. Rhona from Perth put the question that many others echoed:
“Can anyone tell the difference between a flare and IBS? I just discovered that IBS is common after a flare, and the symptoms are so similar.”
Rhona from Perth
Members who live with both describe the same dividing lines: how severe the pain is, whether appetite disappears, and how urgent the toilet trips feel.
“With diverticulitis I get severe pain and lose my appetite. With an IBS attack I don’t get much pain, I just have to run to the toilet many times, fast.”
Valerie from Exeter
“IBS is more like things are just off: bloating, cramping, constipation or diarrhoea, without that same level of active severe inflammation.”
Trevor from Carlisle
The NHS confirms that the symptoms of diverticular disease and diverticulitis are similar to those of IBS. These member observations are personal patterns, not diagnostic criteria, and a scan or blood test separates the two where symptoms do not. Our article on what can be mistaken for diverticulitis covers the other look-alike conditions in depth.
What Did Members’ Doctors Suspect First?
The discussion contains a pattern that no clinical guideline captures: the other explanations members were given before diverticulitis, or instead of it.
What Doctors Suspected | What Members Reported |
Urinary tract infection | One member who went to the emergency department with severe pain received antibiotics for a urine infection after a small amount of bacteria appeared in her urine. A previous CT report had already named diverticulitis. |
Appendicitis or infection | A member attended A&E during her first ever flare and heard that doctors suspected appendicitis. The cause was diverticulitis. |
Muscular back pain | A new member asked about her mother’s back pain, which the doctor called muscular. Other members suggested a urine test to rule out a urine infection, or a scan to look for a bowel cause. |
Crohn’s disease | One member’s colonoscopy report described the findings as suggestive of Crohn’s disease and asked for a repeat colonoscopy in three months. |
NICE explains why the list is so long. The differential diagnosis for these symptoms includes irritable bowel syndrome, inflammatory bowel disease, colorectal cancer and, in females, ovarian or other gynaecological conditions. Because diverticular disease presents on average in the early sixties, many patients also meet the referral criteria for suspected colorectal cancer, so doctors investigate rather than assume.
That investigation frightens people. Carys from Newport said the pain scared her more because her father had died of bowel cancer. A clear explanation of which tests rule out which conditions addresses that fear directly, which is why this article sets them out.
Does Age Change How Doctors Read The Pain?
Yes. NICE reports an average age at presentation in the early sixties, and BMJ Best Practice lists age over 50 as a risk factor, so doctors expect diverticulitis in your age group. Younger patients face a different problem. NICE notes that diagnosis in younger patients can be delayed, because abdominal pain alone does not usually trigger investigation.
A published case report shows how this plays out. A 20-year-old man arrived with three days of upper abdominal pain that moved to the right lower abdomen, with diarrhoea and nausea. The authors note that appendicitis is far more common at that age, which made the presentation misleading, and a CT scan showed diverticulitis. The report also describes rising rates of diverticulitis in people under 40, although most younger people with diverticulosis never develop symptoms.
“I ended up in A&E with what the doctor thought was appendicitis or an infection, but it was diverticulitis. It was my first flare-up ever, and I’m only 31.”
Zoe, 31, from Hull
Our article on what age people get diverticulitis covers the age data in full.
Which Tests Confirm Diverticulitis?
A GP starts with questions about your symptoms and an examination, and the NHS says further tests may be needed to confirm the diagnosis and rule out other conditions. BMJ Best Practice lists a full blood count, urea and electrolytes and C-reactive protein (CRP) as the first investigations. It names contrast CT of the abdomen as the imaging of choice, and lists ultrasound and MRI as alternatives to consider. NHS Lothian’s clinician guidance states that a full blood count and CRP help to separate uncomplicated diverticular disease from diverticulitis.
Test | What It Shows | Source |
Full blood count | A raised white blood cell count points to infection or inflammation | BMJ; NHS Lothian |
C-reactive protein (CRP) | A marker that rises with inflammation, without showing where the inflammation sits | BMJ; NHS Lothian |
Urea and electrolytes | Kidney function and hydration status | BMJ |
CT scan of the abdomen | Shows the inflamed pouches and the severity of inflammation, and helps exclude other causes of pain | BMJ; case report |
The case report quotes a sensitivity of 93 to 96% and a specificity of 100% for CT in acute diverticulitis, and notes that it separates complicated from uncomplicated disease. One member recommended the CRP blood test to another, and a second member said she had the same test.
“Ask the doctor about the CRP blood test, which rises with inflammation. I had a massive attack, and they gave me a blood form so I could have the test if I suspected a bad flare-up.”
Gillian from Harrogate
Other members could not find the same route. Lorna from Norwich replied with the access problem that many UK members described:
“I had never heard of that. I have to go through the 12-hour A&E wait to get a blood test done.”
Lorna from Norwich
Lorna’s reply shows that access to blood tests differs between members. Rosalind from Salisbury urged members to keep asking questions when routine tests come back normal:
“Please don’t be fobbed off. Keep questioning and requesting tests, there are more tests that can be done.”
Rosalind from Salisbury
Our article on whether a colonoscopy is as bad as people fear covers the investigation that doctors often arrange once a flare has settled.
Why Do Some Members Find Out Years Later?
NICE states that most people with diverticulosis have no symptoms, and that doctors usually find uncomplicated diverticula incidentally, during a CT scan or colonoscopy arranged for another reason or during bowel cancer screening. Our members describe the human side of that finding: a word in a report, and no explanation.
“The doctor stopped by my bed afterwards and said, ‘I couldn’t believe all of the pockets I saw.’ No follow-up appointment, no medical help or information.”
Gwen from Shrewsbury
“When I told my GP I had it, she said, ‘Who told you that?’”
Eileen from Stockport
“I had it and didn’t know, and it was not mentioned. I was told it is very common, that’s it.”
Norma from Dundee
The longest delay in the discussion lasted three years. Hilary from Swindon had a colonoscopy, ultrasounds, several CT scans and repeated blood tests, and heard after each one that the results looked normal. An urgent care doctor then told her she had diverticulitis, and her own records confirmed it.
“I went back through all of my medical records from the past three years. An earlier CT scan explicitly stated that I had diverticulitis.”
Hilary from Swindon
“I previously assumed doctors carefully read every report, but I now realise how important it is to advocate for myself and verify the complete details.”
Hilary from Swindon
Wording matters in these reports. A report that says diverticulosis describes pouches without symptoms, while diverticulitis describes inflamed or infected pouches, as the NHS explains. One member asked Hilary which word her reports used, because in her experience doctors often treat a finding of diverticulosis as minor. Our article on the difference between diverticulitis and diverticulosis explains the terms.
These accounts describe communication gaps and do not describe every clinician. Other members report GPs who explained results clearly and supported them through flares, and one member found a GP who lives with the condition herself.
How Do Members Decide Between Waiting And Seeking Help?
Irene from Falkirk asked the question that sits at the centre of this article. Her latest flare felt different from her first, and she no longer knew what her pain meant:
“The pain was not this severe last time. The doctor who treated me said it varies with each flare-up. So what I can expect is different pain each time, but how will I know if I need antibiotics, a regular doctor’s visit, or hospital?”
Irene from Falkirk
The NHS lists specific situations where you should ask for an urgent GP appointment or get help from NHS 111, and says that serious complications of diverticulitis are rare. Members whose care was delayed describe the other side of that risk.
“I got passed over by my own GP and two doctors at A&E in the days before my emergency surgery.”
Moira from Stirling
Our article on when to get medical advice about diverticulitis sets out the warning signs, and our piece on whether diverticulitis is a serious problem puts the risks in proportion.
How Can A Symptom Diary Help You Describe Your Pain?
Doctors diagnose diverticulitis from a pattern, and a dated record shows the pattern better than memory does. Members who log their symptoms arrive at appointments with specifics instead of impressions. The table sets out what each detail tells a clinician.
What To Record | Why It Matters |
Whether the pain is constant or stop-start | NHS Inform separates diverticulitis (constant and severe) from diverticular disease (intermittent). |
How quickly the pain built | Diverticulitis develops over a day or two. |
Temperature readings | Fever is a key diagnostic factor, although members report serious illness without one. |
Appetite and bowel changes | Members use loss of appetite and urgency to tell diverticulitis from IBS, and NICE records changes in bowel habit as typical. |
Dates and results of scans and blood tests | Members found years-old reports that named diverticulitis. A log lets you ask what each result means. |
Our food and symptoms diary records pain, bowel changes and food in one place, so you can show a doctor how your symptoms moved over days or weeks.
Frequently Asked Questions
Can I Diagnose Diverticulitis Myself?
No. The NHS says a GP asks questions about your symptoms and may arrange tests to confirm the diagnosis and rule out other conditions. NICE’s evidence review found that the symptoms alone are not specific enough to diagnose diverticular disease.
Is Diverticulitis Pain Constant Or Does It Come And Go?
NHS Inform describes diverticulitis pain as constant and severe, and diverticular disease pain as intermittent. Irene’s doctor told her that pain also varies between flares in the same person, so a different pain from last time does not rule diverticulitis out.
Can A Blood Test Show Diverticulitis?
A blood test shows inflammation, not its source. BMJ Best Practice lists a full blood count and CRP among the first investigations, and NHS Lothian’s guidance says they help separate uncomplicated diverticular disease from diverticulitis. A CT scan shows where the inflammation sits.
Why Did A Scan Mention Diverticulitis When Nobody Told Me?
Scans and colonoscopies arranged for other reasons often show diverticula, and NICE notes that doctors usually find uncomplicated diverticula this way. Reports use the words diverticulosis and diverticulitis for different findings. Ask your GP to explain the exact wording in your report and what it means for you.
Can Diverticulitis Cause Weight Loss?
NHS Inform states that diverticular disease does not cause weight loss. It advises seeing your GP if you are losing weight, seeing blood in your stools or having frequent bowel changes, because those symptoms need their own investigation.
More Reading
Key Takeaways
- Pain alone does not confirm diverticulitis. NICE found the symptoms too non-specific, and doctors use blood tests and a CT scan to confirm it.
- Diverticulitis pain is constant, severe and develops over a day or two. Diverticular disease pain comes and goes.
- Fever supports the diagnosis, but five members described serious illness without one. Blood tests measure what a thermometer misses.
- Members were first given diagnoses including urine infection, appendicitis and Crohn’s disease. Many look-alike conditions share these symptoms.
- Several members learned they had diverticular changes from an old report. Reading your own reports and asking what the wording means closes that gap.
- A dated symptom diary gives your doctor a pattern to work with.
Sources And Further Reading
- NHS: Diverticular disease and diverticulitis
- NICE evidence review: Diverticular disease, signs and symptoms, and indications for investigation
- BMJ Best Practice: Diverticular disease (subscription required for full access)
- Case report: Acute diverticulitis, a rare cause of abdominal pain (PMC)
- NI Direct: Diverticular disease and diverticulitis (NHS Inform content)
- NHS Lothian: Diverticular disease clinician guidance
If you are working out what your own pain means, you are not doing it alone. Our support forum and Facebook group bring together members comparing exactly these experiences, alongside the evidence.
Disclaimer: This article does not constitute medical advice. Always seek advice from a qualified medical practitioner about your own symptoms, diagnosis or treatment.
