Abdominal pain is the IBS symptom that most drives how severe the condition feels.[1] It's real pain, and it can be measured. It comes from the way the gut senses ordinary events, like stretching from gas and stool or a strong squeeze of the bowel wall, and from how the brain handles those signals. In IBS, both are turned up.[2][3]
Why is IBS so painful?
- An oversensitive gut (visceral hypersensitivity). In a classic 1973 experiment, a balloon inflated to 60 mL in the lower colon caused pain in 55% of people with IBS but only 6% of controls.[4] A later study found altered sensation in the rectum in 94% of 100 people with IBS.[2] Across five groups totaling more than 1,100 patients, the more sensitive the gut, the worse the symptoms, even after allowing for anxiety and depression.[3]
- A brain that turns the volume up. A meta-analysis of brain-imaging studies found that, when the rectum was stretched, people with IBS showed more activity in brain regions linked to emotional arousal and pain modulation. Healthy people engaged more of the regions that help regulate such signals.[5]
- Powerful contractions. In people with IBS with pain and diarrhea, strong contractions that sweep through the colon were more frequent and more forceful than in healthy volunteers, and more than 90% of them came with pain.[6]
- Gas and stretching. After a drink containing a fermentable fiber (inulin), people with IBS produced no more gas than healthy people, yet they had more symptoms, and their pain rose with the amount of gas in the colon.[7]
- Stress and poor sleep. Stress changes gut sensitivity and motility and can trigger flare-ups,[8] and in women with IBS a bad night's sleep predicted more abdominal pain the next day.[9]
Where is IBS pain felt?
Anywhere in the abdomen, and it can move. UK guidelines note that IBS pain can occur anywhere in the belly and vary in site, unlike cancer-related pain, which typically stays in one fixed place.[10] When researchers inflated balloons at different points along the colon, people with IBS felt pain in any part of the abdomen. It often matched their usual pain, and sometimes it was felt outside the abdomen altogether.[11]
Lower-belly pain is the classic pattern. In the 1973 balloon study, people who felt pain located it in the lower middle abdomen (40%), in one or both lower sides (31%), in the rectum (21%), or in the back or elsewhere (8%).[4] Upper-abdominal pain is common too: in one Asian study, more than half of people with IBS placed their pain in the upper abdomen.[12] If yours spreads to your back, see can IBS cause back pain?
What does IBS pain feel like, and how long does it last?
- It's linked to your bowels. Under the Rome IV criteria, IBS pain is related to bowel movements, or to changes in how often you go or what your stool looks like.[13] It may ease after you pass stool or gas, or it may get worse.[12]
- It comes in episodes. People with IBS most often call them flare-ups or attacks, and some describe "cramp attacks." In one US study, the most common answer was that episodes were totally unpredictable, and fewer than 3% of people said they were totally predictable.[1]
- Episodes usually last days, not weeks. In a three-month diary study, spells of significant pain lasted about 3 days on average. More than half of them happened outside spells of diarrhea or constipation.[14]
- It keeps coming back. A diagnosis needs pain on at least 1 day a week, on average, over the last 3 months.[13]
For more on timing, see how long an IBS flare-up lasts.
What helps IBS pain?
| Option | What the evidence says |
|---|---|
| Antispasmodics (medicines that relax gut muscle) | A first-line treatment for IBS pain in UK expert guidance. An Asian consensus rated the evidence for pain relief as high.[15][12] |
| Peppermint oil | Better than placebo for pain in a meta-analysis of 10 trials: about 1 extra person in 7 improved. Side effects were more common, and the evidence quality was very low.[16] |
| Low-dose tricyclic antidepressants | Used in IBS as gut–brain neuromodulators, a second-line option when first-line treatments don't help.[15] |
| Gut-directed psychological therapy | CBT and gut-directed hypnotherapy have the largest evidence base and the best long-term results among psychological therapies for IBS.[17] |
| Low-FODMAP diet, short term, with a dietitian | Ranked first for abdominal pain among the diets compared in a network meta-analysis.[18] See the low-FODMAP guide. |
| A heat pad | A low-risk comfort measure for cramps, but it hasn't been properly studied in IBS. Keep it warm, not hot, to avoid burns. |
Ask a doctor or pharmacist before starting or combining medicines.
What should you track?
Rate your pain, note when it starts, what you ate in the hours before, your stool type and whether a bowel movement eased it. People who can predict their pain episodes report better quality of life, and the researchers suggest a journal to help people who can't.[1] IBS Clue, an iPhone app coming soon, records pain with a severity rating at each check-in and looks for links with what you ate.
When to see a doctor
- Pain that is new, different from your usual pattern, or stays in one fixed spot[10]
- Pain that wakes you from sleep[12]
- Pain with fever, blood in your stool, weight loss you can't explain, or anemia[12]
Get urgent care if pain starts suddenly and is severe, you vomit blood, your stool is black and sticky, or you can't pass stool or gas at all.[19] See also IBS red flags.