Diverticulitis typically feels like a steady, persistent pain in the lower left side of your abdomen that comes on relatively suddenly and doesn’t go away. Unlike gas pain or a stomach bug, the pain is constant rather than coming in waves, and it often gets worse over the course of a few days rather than better. Most people describe it as a deep ache or pressure, sometimes sharp, that makes you not want to move or press on that area.
Where the Pain Shows Up
The lower left abdomen is the most common location because that’s where the sigmoid colon sits, and it’s the section of the large intestine most prone to developing the small inflamed pouches that define diverticulitis. The pain tends to be localized, meaning you can usually point to the spot that hurts rather than feeling a vague, all-over discomfort.
There’s an important exception: people of Asian descent are more likely to develop right-sided diverticulitis, which causes pain in the lower right abdomen. This can feel almost identical to appendicitis, with sharp right-sided pain, fever, and nausea. It’s common enough in Asian populations that doctors in those regions consider it routinely, but in Western countries it’s rare and can lead to misdiagnosis.
How It Differs From Gas or IBS
If you’re wondering whether what you’re feeling is diverticulitis or something less serious, the key distinction is what happens after you have a bowel movement. IBS pain and trapped gas typically ease or resolve once you pass stool or gas. Diverticulitis pain does not. It stays constant regardless of what your gut does.
Other differences that point toward diverticulitis rather than IBS or general digestive discomfort:
- Sudden onset: Diverticulitis pain usually arrives within hours, not gradually over weeks.
- Fever and chills: These signal an active infection or inflammation that IBS doesn’t cause.
- Abdominal tenderness: The area hurts when you press on it, and your muscles may tighten involuntarily to guard the inflamed spot.
- Nausea or vomiting: More common with diverticulitis than with IBS flares.
IBS, by contrast, is more likely to involve cramping that shifts around, mucus in your stool, and symptoms that wax and wane with stress or diet changes.
What the Pain Feels Like Day by Day
Most people notice discomfort that starts as a dull ache or mild tenderness and builds over several days. By the time many people seek medical care, the pain has been present and worsening for two to three days. It’s typically severe enough to interfere with normal activity. Sitting, walking, or coughing can make it worse because those movements jostle the inflamed section of colon.
The pain often feels deeper than surface-level soreness. It’s not a sharp stitch like a side cramp from running. It sits lower in the abdomen and has a heavy, pressurized quality. Some people describe it as feeling like something is swollen inside them, which is essentially what’s happening: one or more pouches in the colon wall have become infected and inflamed.
Symptoms Beyond the Pain
Diverticulitis is an inflammatory condition, so it usually brings more than just abdominal pain. Fever is common, ranging from low-grade to more significant depending on severity. You may feel generally unwell in a way that’s hard to pin down, similar to the early stages of the flu.
Bowel habits often change. Constipation is the more frequent pattern, though some people develop diarrhea instead. You might feel bloated or notice that your abdomen looks distended. Nausea is common, and some people vomit, especially if the inflammation is significant. A reduced appetite is typical. Many people simply don’t feel like eating.
Less commonly, the inflammation can irritate nearby structures like the bladder, causing an urge to urinate more frequently or discomfort during urination. This happens because the sigmoid colon sits close to the bladder in the pelvis.
Signs That Something More Serious Is Happening
Most diverticulitis episodes are uncomplicated, meaning the inflammation responds to treatment without causing structural damage. But complications can develop, and they change how the condition feels in noticeable ways.
If the pain suddenly becomes much worse and spreads across your entire abdomen rather than staying in one spot, that can indicate a perforation, where one of the inflamed pouches has ruptured. Your abdomen may become rigid and extremely tender to any touch. This is a medical emergency. A high fever alongside rapidly worsening pain is another red flag.
An abscess, which is a walled-off pocket of infection, tends to cause persistent fever that doesn’t improve and deep, throbbing pain that stays intense rather than fluctuating. Blood markers of inflammation rise sharply with complicated disease. Doctors use these levels to gauge severity: patients with uncomplicated diverticulitis show markedly lower inflammation than those with abscesses or perforations.
What Recovery Feels Like
With treatment, most uncomplicated flares start to improve within two to three days. The pain gradually dulls, your appetite returns, and the fever breaks. Full resolution typically takes a week or so, though some tenderness in the area can linger. You may notice your bowel habits take a bit longer to normalize.
If you’ve had one episode, you’ll likely recognize the sensation if it recurs. Roughly one in five people who have diverticulitis will experience another flare at some point. Paying attention to that familiar lower-left ache and early tenderness can help you seek care sooner the next time, before symptoms escalate.