Seven stool types, recorded per bowel movement or once a day on the participant's phone. Private, quick and structured, so stool form can become an endpoint instead of an anecdote.
Free sandbox · No credit card · 21 CFR Part 11 aligned
Bowel diary
Today · Movement 2
Which type best describes this stool?
Urgency
At a glance
Use in trials
Gastrointestinal trials in irritable bowel syndrome, chronic constipation, inflammatory bowel disease, microbiome interventions and some oncology supportive care studies all need a reliable record of bowel habit. The Bristol scale gives that record a common language: instead of "loose" or "normal", each movement gets a type number that can be counted and compared.
Endpoints are usually built from daily data: the proportion of days with type 6 or 7 stools, the number of complete spontaneous bowel movements per week, or a weekly responder definition combining stool form with abdominal pain. Those endpoints need daily entries, which is why the diary format and compliance matter more than the scale itself.
Recording every bowel movement gives the richest data but is more demanding. A once-daily diary asking for the number of movements and the most typical type is often enough. Choose based on your endpoint definition, and keep it the same throughout.
Participants often find the scale easier with illustrations; if you use them, use an approved version and keep the text descriptions. A phone diary lets participants record privately, at the time, rather than recalling details at a clinic visit.
Movements
11
Type 6-7 days
1
Diary days
7/7
In Capture
The Bristol diary runs as a recurring questionnaire in the participant's phone browser, with a daily completion window and reminders that respect quiet hours. The dashboard shows compliance, so missed days are followed up before a weekly responder calculation is compromised.
Build it in the free sandbox and complete a test entry.
Endpoints
Regulatory guidance for irritable bowel syndrome trials uses composite weekly responder definitions that combine abdominal pain with a bowel measure: stool consistency (for example days with type 6 or 7 stools) in diarrhoea-predominant IBS, and complete spontaneous bowel movements in constipation-predominant IBS. A participant is a responder in a week if both criteria are met, and an overall responder if they respond in enough of the treatment weeks.
Those definitions need the daily diary to capture the right fields: stool type, whether the bowel movement was spontaneous (no laxative in the preceding period), whether evacuation felt complete, and daily worst abdominal pain. Build the diary from the endpoint definition backwards, and keep the questions identical for the whole study.
Before go-live
Diary fields derived from it.
Needed to classify spontaneous movements.
Worst pain in the last 24 hours on a 0 to 10 scale.
Per week, for a week to count.
Long enough to establish usual bowel habit.
If used, an approved version of the scale.
A bowel movement without laxative use in the preceding period (commonly 24 hours) that gives a feeling of complete evacuation. It is the key bowel measure in constipation trials.
Long enough to establish usual bowel habit and confirm eligibility, often around two weeks. The protocol sets the exact period and the minimum number of diary days.
A seven-type classification of stool form, from separate hard lumps (type 1) to entirely liquid (type 7).
Types 3 and 4 are typically considered normal; 1 and 2 suggest constipation and 5 to 7 suggest diarrhoea.
In daily diaries, often combined with abdominal pain in weekly responder definitions.
It depends on the endpoint. Per-movement recording is richest; a daily summary is less burdensome.
Yes, in the free sandbox.
Private, daily, structured. Free sandbox.