IBS flare-up symptoms: what they feel like and what to log

What an IBS flare-up feels like

The NHS lists four main symptoms of IBS: stomach pain or cramps that are usually worse after eating and better after a bowel movement, bloating, diarrhea and constipation. NIDDK, part of the National Institutes of Health, describes the most common symptoms as belly pain often related to bowel movements, plus changes in bowel movements that may be diarrhea, constipation or both, depending on the type of IBS.

Other symptoms can come along, including the feeling that you have not finished a bowel movement, mucus in the stool, gas, tiredness, nausea, pelvic pain and needing to urinate often. IBS is chronic and often lasts for years, but NIDDK notes that the symptoms may come and go. The NHS calls the worse days flare-ups.

What can set off a flare-up

Sometimes there is no obvious reason. The NHS lists these triggers: alcohol, caffeine, certain foods such as spicy or fatty food, stress and anxiety, and regular antibiotic use. NIDDK adds that women with IBS often have more symptoms during their periods.

Fiber can work both ways. NIDDK says adding fiber slowly, by 2 to 3 grams a day, may help prevent gas and bloating, because too much fiber at once can cause gas that triggers IBS symptoms. NIDDK also lists foods rich in FODMAPs, which are hard-to-digest carbohydrates, and says some people with IBS have more symptoms after eating gluten even without celiac disease.

What to log to find your triggers

The NHS advises keeping a diary of what you eat and any symptoms you get. These details are our own suggestions for what to write, and they are the same ones our food and symptom diary guide explains in more depth.

• What you ate and drank, with the time and a rough amount
• Each symptom with its time and a 0 to 10 strength: pain, bloating, nausea, gas
• Each bowel movement, with its Bristol Stool Chart type
• Stress, sleep and anything unusual that day, such as travel
• Your period, if it applies, and any new medicine or antibiotic
• What you did to cope, and whether it helped

What to do during a flare-up

The NHS says no single diet or medicine works for everyone with IBS. Its suggestions include eating a balanced diet, drinking at least 8 to 10 drinks (about 1.5 liters) a day, finding ways to relax, getting plenty of exercise, not skipping meals and not eating too quickly. It advises against lots of fatty, spicy or processed food, more than 3 caffeinated drinks a day, and lots of alcohol or fizzy drinks.

For bloating and gas, the NHS suggests regular oats and avoiding hard-to-digest foods such as cabbage, broccoli, beans and onions. For diarrhea it suggests cutting down on high-fiber foods and drinking plenty of water, and for constipation, more water and soluble fiber such as oats and carrots. For any of these, the NHS suggests asking a pharmacist about medicines that can help.

A low-FODMAP diet is a short, planned trial, not a way to eat for a flare-up day. The American College of Gastroenterology guideline recommends a limited trial of it to improve global IBS symptoms, and NIDDK says a doctor may recommend a dietitian and then slowly adding the foods back.

When to see a doctor

The NHS says to see a doctor if you think you have IBS and have had symptoms for more than 4 weeks, so they can check and rule out other problems. It also says to ask for an urgent appointment or call 111 in the United Kingdom if you have lost a lot of weight for no reason, you are bleeding from the bottom or have bloody diarrhea, you find a hard lump or swelling in your belly, or you have shortness of breath, noticeable heartbeats and unusually pale skin. In the United States, call your doctor promptly or seek urgent care for these signs.

NHS also advises seeing a doctor if diet changes and pharmacy medicines are not helping, or if you need to avoid lots of different foods to control symptoms. Do not label every bad stomach day as IBS yourself, because the same symptoms can come from other conditions.

How a log helps at the appointment

The American College of Gastroenterology guideline suggests a positive diagnostic strategy for IBS, which means diagnosing by the symptom pattern instead of ruling out everything else first. It also suggests blood tests for celiac disease in people with IBS and diarrhea symptoms, and a fecal calprotectin test in people with suspected IBS and diarrhea, to rule out inflammatory bowel disease.

A log gives the clinician the pattern: how often the flare-ups come, which symptoms lead, and what happened around them. Bring a few weeks of entries rather than a memory of the worst days.