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Calcimator

Bristol Stool Scale Calculator

Classify stool form on the Bristol Stool Scale (types 1–7), estimate colonic transit time, and screen for functional constipation or diarrhea criteria.

Inputs

Results

Classification (0=Constip, 1=Normal, 2=Diarrhea)

1

Est. Colonic Transit (hours)

24

Functional Symptom Score (0–9)0
Frequency (0=Low, 1=Normal, 2=High)1
Meets Constipation Criteria (0/1)0
Meets Diarrhea Criteria (0/1)0
Fiber Recommendation (g/day)25
Hydration Goal (mL/day)2,000
Total BMs in Period7
Constipation Criteria Met0
How to Use This Calculator
  1. Enter your Bristol Stool Type (1–7): 1 is hard lumps, 4 is ideal, 7 is liquid.
  2. Enter Frequency Per Day, Days Tracked, Urgency (0–3), and Straining (0–3).
  3. Enter Incomplete Evacuation score (0–3) to capture symptom burden beyond stool form.
  4. Review Stool Classification (constipation, normal, or diarrhea) and Estimated Colonic Transit Time.
  5. Check Functional Symptom Score to assess overall GI functional status for clinical discussion.

What each input means

Bristol Stool Type
Select Bristol Stool Scale type.
Bowel Movements per Day
Average BMs per day. Normal range: 0.4 (3/week) to 3/day.
Days Tracked
Number of days over which this pattern has been tracked.
Urgency
Degree of urgency.
Straining
Degree of straining during bowel movements.
Incomplete Evacuation
Sensation of incomplete evacuation.

What each result means

Classification (0=Constip, 1=Normal, 2=Diarrhea)
Types 1–2 = constipation, 3–4 = normal, 5–7 = diarrhea tendency.
Est. Colonic Transit (hours)
Estimated colonic transit time. Normal: 12–48 hours.
Functional Symptom Score (0–9)
Combined urgency + straining + incompleteness score.
Frequency (0=Low, 1=Normal, 2=High)
0 = <3/week (infrequent), 1 = normal, 2 = >3/day (excessive).
Meets Constipation Criteria (0/1)
Simplified Rome IV functional constipation screen (≥2 criteria).
Meets Diarrhea Criteria (0/1)
Simplified IBS-D pattern screen (≥2 criteria).
Fiber Recommendation (g/day)
Recommended daily fiber intake based on stool pattern.
Hydration Goal (mL/day)
Daily fluid intake recommendation.
Total BMs in Period
Estimated total bowel movements during the tracking period.
Constipation Criteria Met
Number of functional constipation criteria met (out of 4 screened).

How this is calculated

Worked example, using the default values

  1. Identify Input Parameters
    4 parameters
    Bristol Stool Type = 4, Bowel Movements per Day = 1, Days Tracked = 7, Urgency = 0 = 6 input(s) provided
  2. Calculate Classification
    Classification = classification
    1 = 1
  3. Calculate Est. Colonic Transit
    24 = 24
  4. Calculate Functional Symptom Score
    Functional Symptom Score
    0 = 0
  5. Calculate Frequency
    1 = 1

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