How to Record Alcohol and Caffeine in a Symptom Diary Without Judging Yourself

Write down what you drank, how much, and roughly when, using the same words you would use for any other drink. For alcohol, “two 175 ml glasses of red wine with dinner” is more useful than “a couple of drinks”, and you can convert it to units later if you want to. A diary is a record, not a report card, so there is no need to shave the numbers. The aim is to be able to compare a day with alcohol or caffeine with a day without, not to prove anything about either.

This guide covers alcohol, plus caffeinated drinks that are not plain tea or coffee. For water, tea, coffee and fizzy drinks in general, see how to record water and other drinks, which deliberately leaves alcohol out.

Why alcohol belongs in the record

Alcohol can plausibly change what a digestive day looks like, and it usually arrives with a meal, a late night and a different routine. That makes it a candidate for a confounder: something that sits alongside a food and may be part of the story instead.

A 2000 narrative review of alcohol and the gastrointestinal tract by Bujanda in the American Journal of Gastroenterology reports that alcohol weakens the valve at the lower end of the gullet and disturbs its movement, which promotes reflux. It also reports that small amounts speed the emptying of the stomach while large amounts slow it and reduce bowel movement, and that diarrhoea is among the intestinal problems linked to alcohol. The review is old, it is not a systematic review, and it describes general effects rather than what will happen to you on a given evening.

The practical point is that the amount matters as well as the fact of drinking. “No drinks”, “one drink” and “a long evening” are different entries. Whether any of this explains your own symptoms is a question a diary can only inform, not settle.

A short alcohol entry

Aim for four details, and skip any that do not apply:

1. What: beer, wine, spirit, cocktail, or the brand and strength if you know it.
2. How much: the glass, bottle or measure, such as “pint”, “330 ml bottle” or “large glass”.
3. When: the time you started and whether it was with food, before food or after.
4. Anything unusual: a stronger drink than usual, a mixer, an unfamiliar cocktail, drinking when you were already unwell.

You do not need units on the spot. Writing what you had and how much is enough, and you can convert it afterwards.

Converting to units, if you want to

The NHS defines one unit as 10 ml, or 8 g, of pure alcohol. To work out the units in a drink, multiply its strength (ABV, shown on the label) by its volume in millilitres and divide by 1,000. The NHS example is a pint (568 ml) of 5.2% lager, which comes to about 2.95 units.

The NHS page gives some reference points for a 12% wine: 125 ml is 1.5 units, 175 ml is 2.1 units and 250 ml is 3 units. A 330 ml bottle of 5% beer is 1.7 units, and a 440 ml can of 5.5% beer is 2.4 units. Those figures only apply to the strengths and volumes it lists. A glass poured at home may be larger than the glass sizes above, and the label strength varies between wines and beers, so treat any conversion as an estimate and say so in the entry, for example “about 3 units, home pour”.

Units are one way to compare days, not a rule about what is safe for you. The NHS page also gives the UK guidance of no more than 14 units a week on a regular basis, spread over at least three days. You do not need to measure yourself against that line in a symptom diary.

Caffeine and other drinks that are easy to forget

The drinks guide covers tea and coffee. Two extra notes help when caffeine varies:

• Name the drink and whether it was caffeinated. “Cola”, “energy drink” and “decaf coffee” tell you more than “a drink”.
• Note the days that were unusual. Several coffees on a tired morning is a different day from your normal one.

The British Dietetic Association’s irritable bowel syndrome and diet sheet, dated January 2022 and marked as under review, suggests no more than two mugs (three cups) of caffeine-containing drinks a day. It also suggests keeping a food and symptom diary while making changes so that you can see what has helped. That sheet is written for people with IBS, and your symptoms may not be IBS, so treat it as context for what a dietitian might ask about rather than advice for you.

Keep it free of judgement

It is easy to shade an alcohol entry downwards, or to skip it on a day that felt embarrassing. A record that leaves out the heavier days will quietly make the lighter days look like the whole picture.

Self-reported drinking is a hard thing to measure well. A 2018 systematic review of 28 studies of self-report alcohol measures found that the measures it examined showed adequate or good test-retest reliability, but the authors said it was hard to say which was best, no study assessed every property, and methodological quality varied. That research concerns how drinking is measured in general, not food-and-symptom diaries, so the lesson here is modest: a consistent habit of writing things down as they happen is likely to serve you better than a tidy-looking record.

If you notice that you are leaving things out, say so in the diary: “did not note drinks on Saturday”. It is the same principle as keeping missing check-ins visible rather than letting a blank look like a normal day.

Reading alcohol and caffeine entries when you look back

When you review a week or two, use plain questions:

• On days with symptoms, what had I drunk in the hours before, and was it usual?
• Did the same drink appear on days without symptoms?
• Did a late night, less sleep or a different meal come with it? A drink often arrives alongside sleep and stress changes, and the diary cannot separate them.
• Which days have no drink recorded because I had none, and which because I did not write it down?

“Looser stools followed two of the three evenings with wine, and also one evening without” is an observation with an exception. “Wine upsets my gut” is a conclusion the record has not earned. The same caution applies as in Can You Tell Which Meal Caused Bloating?: something that came before a symptom is not automatically its cause.

When to speak to someone

A symptom diary is not the right place to work out whether your drinking is a problem. The NHS suggests seeing a GP if you often feel the need to have a drink, other people warn you about how much you drink, or you think it is causing you problems. It also warns that if you may be physically dependent, stopping suddenly can be harmful, so get advice first. Drinkline offers a free, confidential helpline on 0300 123 1110.

Speak to a pharmacist, GP or NHS 111 if digestive symptoms are persistent, getting worse or worrying you, and do not wait for a tidy record before asking. If you are thinking about cutting out a drink, mention it to a doctor or dietitian instead of using the diary to decide.

If you would like an easier way to capture drinks alongside meals and symptoms, you can get GutBloom on Google Play.

Sources

• NHS — Calculating alcohol units
• NHS — Alcohol support
• Bujanda L. The effects of alcohol consumption upon the gastrointestinal tract. American Journal of Gastroenterology (2000)
• McKenna H and colleagues. Evaluation of the psychometric properties of self-reported measures of alcohol consumption: a COSMIN systematic review. Substance Abuse Treatment, Prevention, and Policy (2018)
• British Dietetic Association — Irritable bowel syndrome and diet (January 2022)