How to keep a food and symptom diary for IBS
If you have irritable bowel syndrome (IBS), the NHS suggests keeping a diary of what you eat and any symptoms you get, so you can work out what triggers them. It sounds simple, but a diary that's too vague won't show you much, and one that's too detailed is hard to keep up. Here's what to record, for how long, and how to read it.
Why keep one
- Triggers are hard to spot from memory, especially in the middle of a flare.
- Symptoms don't always follow straight after a meal, so you need a record to link them to what you ate.
- It shows what helps. The British Dietetic Association suggests keeping a food and symptom diary while you make changes, so you can see what made a difference.
- It's a useful starting point for a dietitian, if you're referred to one.
What to record
- Everything you eat and drink, with the time and a rough amount. Include snacks, sauces, alcohol and caffeine.
- Symptoms: bloating, stomach pain or cramps, gas, diarrhea, constipation or urgency. Note when they started and rate them from 0 to 10.
- Bowel movements: how often, and what they were like. Many people use the Bristol Stool Chart, which describes seven types, to keep it consistent.
- Other factors: stress, sleep, exercise, your period, and any medicines or supplements.
How long to keep it
Aim for at least two weeks, including two weekends, since many people eat differently at weekends. Keep going while you try any change, such as cutting down on a particular food, so you can see whether it helped. Change one thing at a time, and give your gut time to adjust.
A simple template
| Date | Time | Food and drink | Symptoms (0–10) and time | Bowel movement | Stress, sleep, other |
|---|---|---|---|---|---|
| Tue 8 | 08:00 | Oatmeal with milk, coffee | – | Normal (type 4) | Slept 7 hours |
| Tue 8 | 13:00 | Sandwich, apple, soda | Bloating 5 at 15:00 | – | Busy at work |
| Tue 8 | 19:30 | Pasta with garlic sauce | Cramps 6 at 22:00 | Loose (type 6) | Tired |
Making sense of it
- Look for repeats, not one-offs. A food that's followed by symptoms several times is worth discussing; a single bad day isn't proof.
- Remember the timing. Symptoms in the evening may be linked to lunch rather than dinner.
- Check the usual suspects. The NHS suggests not eating lots of fatty, spicy or processed foods, not drinking lots of alcohol or fizzy drinks, and having no more than three cups of tea, coffee or other caffeinated drinks a day.
- Don't cut out whole food groups on your own. If general changes don't help, see your doctor, who may refer you to a dietitian.
The low FODMAP diet
If simple changes don't work, a dietitian may suggest a low FODMAP diet, which limits certain carbohydrates that the gut doesn't break down easily. It's done in stages: cutting out high-FODMAP foods for a while, then reintroducing them to find your own triggers. The British Dietetic Association recommends doing it with a dietitian or similar professional, so your diet stays nutritionally adequate. A good diary makes both stages much easier.
See a doctor urgently if you lose a lot of weight for no clear reason, or have bleeding from your bottom or bloody diarrhea. The NHS says these could be signs of something more serious than IBS. This guide is general information, not medical advice.
For tracking other symptoms, see how to keep a symptom diary.