What a food diary should show your doctor
Why most food diaries are unusable
The typical diary is a list of meals with notes like "bloated again" attached to some of them. It represents real effort and a clinician can do very little with it, for three reasons.
It usually records only bad days, so there is nothing to compare against. It rarely records timing, so a delayed reaction is indistinguishable from an immediate one. And it is too long to read in the time available.
The five things worth recording
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Frequency
How many days out of the last thirty had symptoms. A rate is clinical information; "quite often" is not.
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Severity
A consistent scale, used the same way each time. The absolute number matters less than using it consistently, because it is the change over time that carries information.
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Stool form, on the Bristol scale
One number, 1 to 7. It is standard clinical language, it distinguishes IBS subtypes, and it is the most frequently omitted useful field.
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Timing relative to meals
Whether symptoms arrive within an hour, several hours later, or the next morning. This is what separates a fast osmotic response from colonic fermentation, and it points at which meal to suspect.
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The days nothing happened
Your baseline rate. Without it, no association means anything, because everything you eat regularly will appear alongside symptoms eventually.
Worth adding if you can
- Sleep and stress. Both change gut sensitivity, and both are common explanations for a pattern that otherwise looks like food.
- Menstrual cycle, if relevant. Cyclical bloating is a recognised pattern and is easy to mistake for a dietary one.
- Medications and supplements, including anything started recently.
- What you have already eliminated, and whether it helped.
The summary to lead with
One page, roughly this shape:
That takes fifteen seconds to read and contains a rate, a severity split, a subtype indicator, a timing signal, a hormonal pattern, and confirmation that coeliac testing is still valid. It is more useful than thirty pages of meals.
What this does for you
It changes how the conversation goes. A vague complaint invites reassurance; documented frequency and stool form invite a plan. It is also the single best protection against being dismissed, because it is much harder to wave away a number than a feeling.
Minthe exports exactly this: a clinician-oriented PDF summary and a full CSV behind it, both free on every tier. It records the days nothing happened by design, because the method depends on them.
Minthe is a wellness and self-tracking tool, not a medical device. It does not diagnose or treat any condition and isn't a substitute for professional medical advice. If you have red-flag symptoms such as blood in your stool, unintentional weight loss, difficulty swallowing, persistent vomiting or a fever alongside gut symptoms, see a clinician rather than tracking them.
Frequently asked
How long should I track before an appointment?
Two to four weeks of reasonably consistent logging is usually enough to show a rate and a pattern. Less than a week tells nobody very much, because there is no baseline to compare against and normal fluctuation looks like signal.
Why do the days with no symptoms matter?
Because they are what create the comparison. If you only record bad days, every food you ever eat appears alongside symptoms and nothing can be distinguished from anything else. The rate of symptoms on days without a suspect food is the number that makes the rest meaningful.
Should I track everything I eat in detail?
No, and trying to is the main reason people give up. Consistency matters far more than completeness. Rough meal contents, timing, and how you felt afterwards, recorded most days, beats an exhaustive record kept for five days and then abandoned.
What format do doctors actually want?
Something short and structured. A one-page summary showing how often symptoms occurred, how severe, stool form using the Bristol scale, and any obvious pattern. Attach the detail behind it, but lead with the summary, because nobody is reading 30 pages during a ten-minute appointment.
Does stool form really need to be included?
Yes, and it is the most commonly omitted useful thing. The Bristol scale is standard clinical language, it distinguishes IBS subtypes, and it is far more precise than describing consistency in your own words. It is one number per entry.