A reminder decides when you are asked about your day, and so it shapes what ends up in the record. The practical rules are short: set reminders for times you can realistically answer, keep the question short, and treat an unanswered reminder as “not recorded”, never as “no symptoms”. The research on reminders is thinner than app marketing suggests, so this article keeps the claims modest.
What the research says about reminders
Reminders are widely assumed to help people keep up a diary, but the evidence is general rather than specific to food and digestion.
A 2021 scoping review of factors that influence the use of electronic diaries in health care (22 studies) lists reminders among the features that could affect use, alongside design and clear feedback. The authors describe notifications as prompting people to complete a questionnaire, which can raise completion. They also report that reminders were rarely the main question of the included studies, that the review did not assess study quality, and that it did not measure how large any effect is. Read it as “reminders are plausibly useful”, not as proof of how much.
So there is no research-backed best time or best number of reminders for a food diary. What you can do is decide from your own routine, then check afterwards whether it worked.
Why the timing of the prompt changes the entry
A reminder sets the moment of recall. Whatever you answer after it is only as good as your memory of the stretch it asks about.
- A reminder soon after a meal can capture what and how much you ate while it is fresh, but any symptom that starts later will not be there yet.
- An evening reminder can look back over the whole day, which is gentler on your attention, but it relies on memory for the morning. The same trade-off is described in adding entries at the time or afterwards.
- A short, fixed question asked the same way each time makes days easier to compare than a long form you only complete when you have energy. Pick-lists, defaults and required fields have the same effect on what gets recorded.
None of these is the correct choice. Pick one pattern, keep it for a few weeks, and note if you change it. A diary whose prompts moved from evenings to after lunch partway through is harder to compare than one with an imperfect but steady routine.
What an unanswered reminder can and cannot tell you
Most unanswered reminders are mundane: the phone was in another room, you were driving, you were busy. Two studies of prompted self-reports, both in the general population rather than in people with digestive symptoms, show how that can look in practice.
In Reiter and Schoedel’s 2024 study, 592 adults in Germany aged 18 to 65 received up to four short questionnaires a day for 14 days; 78.2% of 26,750 prompts were answered. The best predictor of whether someone answered a prompt was how often they had answered before, followed by where they were (at home or at work went with answering more, a rail journey with answering less). Mood and stress were not among the most informative predictors, though the study measured them only at the last answered prompt, sometimes hours earlier. Prompts were also sent only while participants were using their phone, so ignoring a prompt unnoticed was not captured. The authors say missingness is not purely random, and that they cannot rule out that it depends on states they did not observe.
In Compernolle and colleagues’ 2024 pooled analysis, 271 community-dwelling older adults in Flanders answered at least one item after 77.5% of prompts over seven days. Evening prompts were somewhat less likely to be answered than morning ones (odds ratio 0.82, 95% confidence interval 0.69 to 0.97). The authors judged the missingness most consistent with “missing at random”, but because they did not ask why people skipped prompts, they could not exclude missingness that depends on the unobserved answer itself.
Together these are two samples with their own limits, not a rule for your diary. What they support is a cautious reading:
- An unanswered prompt often reflects routine and context more than symptoms.
- It can still reflect how you felt, and a diary alone cannot tell which. The wider issue is covered in how missing symptom check-ins change what a diary can show.
- It certainly does not mean a symptom-free interval. A blank is an unknown.
A simple way to set reminders up
- Choose one or two times you are normally able to answer, for example mid-evening, and optionally one after your largest meal.
- Keep the question short. If a reminder opens a long form, you will be tempted to dismiss it. A short check-in that you actually complete beats a thorough one you skip. Voice notes can be an option when typing is the barrier.
- Decide what a late answer means. If you answer hours later, write that it was a late entry rather than letting it look immediate.
- Mark the gaps. If you notice that a day has no answer, mark it “not recorded” rather than leaving it blank or filling it in from memory. If you did answer and had nothing to report, record “no symptoms” explicitly, so the two cases look different.
- Review the gaps now and then. If unanswered reminders cluster on days you were unwell, travelling or busy, note that beside the entries you do have, and treat any comparison from those days as provisional.
- Turn reminders down when they become a chore. Fewer, better-timed prompts are preferable to a diary you resent. If tracking is making you anxious, the guide on how long to keep a diary covers scaling back.
What a reminder cannot do
A reminder improves the chance that an entry exists. It cannot make the entry accurate, show that a meal caused a symptom, or fill the days you missed. Treat the record the same way as any other: look for repeats, note exceptions, and keep an unresolved gap unresolved.
GutBloom is designed to offer check-in reminders after meals and in the evening that open into a short check-in, and to leave a missing check-in unresolved rather than counting it as symptom-free. If that fits your routine, you can get GutBloom on Google Play. Reminders and the diary around them are tools for observing, not for diagnosing.
When to get advice
Do not wait for a complete diary before seeking care. The NHS advises an urgent GP appointment or contacting NHS 111 if you have bleeding from your bottom or bloody diarrhoea, and lists other warning signs such as unexplained weight loss and a lump or swelling in the tummy. If symptoms persist, a short summary of what you did record is useful; How to Summarise Digestive Symptoms for a GP Appointment shows how. This article has not been professionally reviewed.
Sources
- Daniëls and colleagues — Factors That Influence the Use of Electronic Diaries in Health Care: Scoping Review (JMIR mHealth and uHealth, 2021)
- Reiter and Schoedel — Never miss a beep: Using mobile sensing to investigate (non-)compliance in experience sampling studies (Behavior Research Methods, 2024)
- Compernolle and colleagues — Older adults’ compliance with mobile ecological momentary assessments in behavioral nutrition and physical activity research (Int J Behav Nutr Phys Act, 2024)
- NHS — Symptoms of IBS