III. 12 Reading the symptom diary and the Bristol scale
The diary is not bureaucracy but the compass of your healing. If you learn to read your own data – above all the stool count and the Bristol scale – you can see the improvement yourself and recognise in good time if something isn't right.
You have been keeping the diary from the first day, but so far you have mostly just recorded the data – now you will learn to read it too. The diary, you see, is not an end in itself but the compass of your healing: the daily stool count, the consistency of the stool (the Bristol scale[G]), bloating and how you feel together tell the story of whether your condition is improving, plateauing or worsening. A single day on its own says little – what matters is the trend, that is, the direction that holds over several days. In this chapter you will learn what the numbers of the Bristol scale mean, how to recognise a favourable and an unfavourable trend, and which signs are the ones where you must not wait but turn to a doctor at once. Your diary is, moreover, your treating physician's best aid too – it gives an accurate picture of what happened between two appointments.
The Bristol scale – the common language of stool
The consistency of stool reveals a great deal about the state of your gut, but "loose" or "hard" means something different to everyone. That is why we use a simple, seven-point pictorial scale, the Bristol scale, which classifies stool from liquid to hard:
- Type 1: separate, hard lumps (like small pellets) – severe constipation
- Type 2: sausage-shaped, but lumpy
- Type 3: sausage-shaped, with cracks on the surface
- Type 4: sausage- or snake-shaped, smooth and soft – ideal
- Type 5: soft, well-separated pieces, easily passed
- Type 6: mushy, with ragged-edged pieces – mild diarrhoea
- Type 7: entirely liquid, with no solid part – watery diarrhoea
C. difficile[G] infection is characterised by unformed stool: the clinical definition is at least three stools in the 5–7 range within 24 hours, and of these types 6 and 7 are the most common – frequent, loose, watery stool. During recovery the diary's target is the stable 3–4 band; this is a DiffBiome protocol convention, not a guideline endpoint. When you see in your diary that the type 6–7 days are thinning out and there are more and more 3–4s, that is one of the most telling signs of the flora's engraftment and of healing.
Reading the trend – what to watch
The most important thing you must learn about the diary: don't look at one day, but at the direction. Healing is a fluctuating process, there will be better and worse days – a single bad day does not mean a relapse, just as a single good day does not mean "done". The trend that holds over several days is the reliable signal.
Two numbers together draw the picture. One is the daily stool count: during healing this should decrease. The other is the Bristol value: this should move towards the ideal 3–4 band. If you see that week by week there are fewer bowel movements and more and more days fall into the 3–4 consistency, then you are on the right track. A useful habit is to "look in" once a week on the past week's data: has the picture improved, plateaued or worsened compared with the previous week?
The benchmark warning sign: if, about ten days after starting the course, the stool persistently stays at type 6–7 and the stool count does not decrease, that is not an adequate response – you must signal this to your treating physician, because the course may need adjustment (more capsules or a more concentrated preparation). Bloating, mood and how you feel are also worth watching: these too are part of the trend, and often improve sooner than the stool picture fully settles.
The diary as a shared tool
A well-kept diary is not only for you – it is one of your treating physician's most valuable tools. No one remembers exactly what happened between two appointments, but the diary does not forget: it shows the stool-count and Bristol trend, the fluid intake, how your symptoms have developed, the doses of the course and the LOT number. With this, your doctor gets an objective picture and can make a more accurate decision.
A few practical tips for a good diary. Record daily, preferably at the same time – in the evening, at the end of the day, for example – so that it becomes a habit. Be honest: the diary is not an exam, inaccurate data only misleads you and your doctor. And don't overdo it: you don't have to document every minute, the essential fields (stool count, Bristol, bloody stool, fluids, dose, LOT, how you feel) are enough. At the end of the 90 days, your complete diary gives a picture of your whole journey – and for many patients it is precisely this looking back that is the greatest motivation.
An automatic analysis can also be produced from the diary, which evaluates the 90 days of data and gives feedback on the trends, the tolerability and when it is worth turning to a doctor. Regardless, your own daily "reading" is the most important: you are the one who notices soonest if something changes.
The Bristol Stool Form Scale (BSFS) is a validated, 7-grade visual-descriptive tool for classifying stool consistency, correlating with colonic transit time (Lewis and Heaton 1997 [020]); types 6–7 indicate fast transit/diarrhoea, types 1–2 slow transit/constipation. The case definition of CDI is at least three unformed (Bristol 5–7) stools within 24 hours (McDonald LC 2018 [023]), which is why, in CDI monitoring, daily stool frequency and the BSFS distribution are the two most easily followed symptomatic indicators – no dedicated, diary-based therapeutic-response endpoint has been studied; the target value of the clinical protocol guideline v7.1 is Bristol 3–4, and it explicitly records that type 6–7 persisting after day 10 of the course is not an adequate response – this warrants consideration of dose escalation (DiffBiome 30(V)+, a higher capsule count or a more concentrated preparation).
The diary follows the logic of the Compatibility Test Data / Patient Recommendation: structured self-monitoring (stool count, Bristol, bloating, bloody stool, fluids, dose/LOT, how you feel, sleep, movement, stress) is the input of the 90-day analytic algorithm, which summarises symptom trend (frequency ↓, Bristol normalisation), tolerability and course progression per LOT, and gives a red-flag alert. LOT-level documentation is the basis of the tapering decision and – in case of relapse – of the LOT switch. Signs of bloody stool, persistent fever or an acute abdominal catastrophe require immediate clinical evaluation independently of the symptomatic trend (the override criteria of the SIS system).
Today you make the Bristol scale your own: you learn the seven grades and consciously record your own values. The destination is 3–4.
- Review the seven Bristol grades and identify where you are now;
- Record today's bowel movement(s) precisely: count + Bristol value;
- Note the presence of bloody stool (yes/no) too – this is always a mandatory field;
- Diary: stool count, Bristol, bloody stool, how you feel.
Today you become a bit of an "analyst": you look at the past few days' data and check the direction. Not one day, but the trend matters.
- Review the stool-count and Bristol data of the past 5–7 days in one place;
- Ask the question: is the stool count decreasing? Are more and more days falling into the 3–4 band?;
- If, after day 10 of the course, it is persistently 6–7 and the count is not decreasing → signal it to your doctor;
- Diary: stool count, Bristol, bloating, how you feel, a note about the trend.
Today, as the close of Phase 2, you tidy up your diary so that it can also be used with your doctor. At the same time, you look back over the journey so far.
- Check that the key fields are complete: stool count, Bristol, bloody stool, fluids, dose, LOT, how you feel;
- Prepare a short summary for your doctor: the stool and Bristol trend over the recent weeks;
- Look back over days 43–60: what do you see that is more encouraging than at the start?;
- Diary: summary of the week, questions for the doctor, how you feel and mood.
🍽️ Eating during these days
The theme of these three days is reading the symptom diary and the Bristol scale, and although the three days are primarily about self-monitoring (getting to grips with the Bristol scale – day 58; charting the weekly trend – day 59; the diary as a shared tool – day 60), eating has a role here too: among the diary's items are the consistency of the stool and bloating, which directly reflect how you tolerate the newly introduced plants – so watching the Bristol value and bloating helps you fine-tune the gradual expansion of your diet.
For these days, the Plant Calendar (Appendix F) recommends walnuts (day 58), almonds (day 59) and sunflower seeds (day 60) – three nuts and a seed rich in fibre and good fats. These days fall into the calendar's "diversity[G] / fermentable fibres" (days 51–70) phase, where the aim is the active building of microbiome diversity. The fibre of nuts and seeds is the substrate of the fibre-degrading bacteria, from which short-chain fatty acids[G], including butyrate[G], are formed and nourish the gut lining; walnuts also provide omega-3[G] and polyphenols[G]; while plant diversity strengthens the flora's resilience. It is worth starting these new sources in small portions and following them in the diary together with the Bristol value and bloating, so that you can see what you tolerate well.
During the diary phase (and continuously from here on), record daily:
- daily stool count – core CDI data;
- stool Bristol scale (1–7) – core CDI data;
- bloody stool (yes/no) – core CDI data;
- bloating (0–5);
- fluid intake (target/actual, litres);
- DiffBiome dose (capsules/day) and LOT number;
- how you feel (1–5);
- Sleep (hours + quality 1–5);
- Movement: type + minutes, step count (target/actual);
- Stress level (1–5) and mood (1–5).
Whatever the multi-day trend, in the following cases you must turn to a doctor at once: fresh blood in the stool; high, persistent fever; severe, cramping abdominal pain or a tense, tender abdomen; signs of dehydration (you barely pass urine, dizziness, weakness, confusion); or if you suddenly become much worse. These are not "bad day" categories – they require urgent medical evaluation.
Why does this matter?
The diary is the compass of your healing: the trend of the stool count and the Bristol scale shows whether your condition is improving and signals in good time if the course is not giving an adequate response (persistent 6–7 after day 10). The trend, not the individual day, is what matters. A well-kept diary is at the same time your treating physician's most precise aid, and at the end of the 90 days an honest mirror of your own journey.
References
[020] Lewis SJ, Heaton KW. Stool form scale as a useful guide to intestinal transit time. Scandinavian Journal of Gastroenterology. 1997. Link
The original validation of the Bristol Stool Form Scale. Whole-gut transit time was measured with radio-opaque marker pellets in 66 volunteers, who kept a diary of stool form on a 7-point scale and of defecation frequency. Transit time correlated most closely with stool form (r = -0.54), more strongly than with stool frequency or stool output. When transit time was altered with senna and with loperamide, stool form tracked the change (r = -0.65). Conclusion: recording stool form is a simple and responsive way to monitor change in bowel function — which is why it is suitable for the patient's own diary.
[023] McDonald LC, Gerding DN, Johnson S, Bakken JS, Carroll KC et al. Clinical Practice Guidelines for Clostridium. difficile Infection in Adults and Children: 2017 Update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA). Clinical Infectious Diseases. 2018. Link
Comprehensive IDSA/SHEA clinical practice guideline on the diagnosis, treatment and prevention of C. difficile infection in adults and children. It defines severity categories (non-severe, severe, fulminant) and characterises fulminant disease by hypotension or shock, ileus or toxic megacolon — findings that require inpatient care, intravenous therapy and surgical consultation. For multiply recurrent infection in which antibiotic therapy has repeatedly failed, faecal microbiota transplantation is recommended. This document provides the international frame to which the book's red flags and hospital-referral signs are aligned.