An IBS food and symptom diary that's easy to keep

An IBS diary links three things: what you ate, how your gut felt, and what your stools were like. Kept for a couple of weeks, it helps you and your doctor or dietitian see which days are different, and what came before them.

By The family behind Stool Log · Reviewed 5 November 2026

The three parts of an IBS diary

The NHS suggests people with IBS keep a diary of what they eat and any symptoms they get.¹ Three parts cover most of it.

Stools. Each time you go, note the time and the Bristol type from the Bristol stool chart. IBS can bring diarrhoea, with a sudden need to go, or constipation, with straining and a feeling you couldn't empty your bowels fully.² Note urgency, straining or feeling you hadn't finished, and mucus.

Symptoms. Bloating, cramps, wind, nausea or reflux, with how bad: mild, moderate or severe is enough.

Food and drink. This is where diaries usually fail, because writing down every bite is tiring.

Logging food without logging everything

You don't need a full food diary to learn something. Try this instead:

• Log the foods you suspect and the foods you eat most. Alcohol, caffeine and spicy or fatty food are among the triggers the NHS names.² Add any others you've wondered about, such as dairy, wheat, onion and garlic, beans or fizzy drinks.
• Use the same name every time. "Milk" on Monday and "latte" on Thursday look like two different foods.
• Note big or late meals and skipped meals, not just what was on the plate.
• If you're following a plan from a dietitian, such as low FODMAP, log what the plan asks you to.

Other things worth a line

• Stress, poor sleep or a busy week. Stress and anxiety can trigger IBS flare-ups.²
• Your period, if you have one: women with IBS often have more symptoms during their periods.³
• Medicines and supplements, with the dose.
• Exercise, or long days sitting.

Reading it after two weeks

Look at your worst days first. What came in the day or two before them? Then look at your good days. A food that turns up before most bad days and few good ones is worth raising with your doctor or dietitian.

Be careful with small numbers: a food you ate twice tells you little. And a link isn't a cause. IBS flare-ups can happen for no obvious reason,² and stress, sleep and your cycle can all line up with a food by chance.

Taking it further, safely

Cutting out foods one after another makes it hard to know what helped. NICE, which writes guidance for doctors in England, says advice on cutting out foods, such as a low FODMAP diet, should only come from a healthcare professional with expertise in diet.⁴ A GP can refer you to a dietitian, and your diary is exactly what they'll want to see.

IBS is diagnosed by a doctor, who may do some tests to rule out other problems first.²

If you'd like a paper version, print our one-week stool diary. It has a column for food and symptoms next to each visit.

This article is general information, not medical advice. Talk to a doctor or nurse about your own symptoms.