IBS-C
With constipation
Mostly hard, lumpy stools that are difficult to pass.
1
2
3
4
5
6
7
Types 1–2Associated with harder, drier stool
ResourceIBS basics4 min read
IBS subtypes, at a glance
IBS-C, IBS-D, IBS-M, and what typical stool forms actually look like. A visual reference based on the Bristol stool scale and Rome IV criteria.
GS
The GutSpy team
Updated April 2026
Key takeaways
- IBS subtypes are defined by stool form, not frequency, using the 7-point Bristol stool scale.
- IBS-C (constipation) leans toward Bristol types 1–2. IBS-D (diarrhea) toward 6–7. IBS-M (mixed) swings across both.
- Subtypes can shift over time. Two weeks of consistent logging is the cleanest way to see your current pattern.
Visual reference
The four patterns, side by side
Each row highlights which Bristol types are typically seen in that subtype. Greyed-out tiles are not part of that group.
1
Separate hard lumps
2
Lumpy sausage
3
Cracked sausage
4
Smooth & soft
5
Soft blobs
6
Mushy, fluffy
7
Entirely liquid
Constipation · Types 1–2
Healthy · Types 3–4
Diarrhea · Types 5–7
IBS-D
With diarrhea
Mostly loose, mushy or liquid stools, often urgent.
1
2
3
4
5
6
7
Types 6–7Associated with looser, more watery stool
IBS-M
Mixed pattern
Alternates between hard and loose stools across days or weeks.
1
2
3
4
5
6
7
Types 1–2 & 6–7Both ends of the scale, at different times
Typical forms
Well-formed stool
Sausage-shaped, smooth or with small cracks, easy to pass.
1
2
3
4
5
6
7
Types 3–4The stool form most people aim to see most days
Based on the Bristol stool scale and Rome IV criteria.
What each subtype means
Four patterns, in plain language
IBS-C
With constipation
Mostly hard, lumpy stools that are difficult to pass. Most Bristol logs fall into types 1–2.
Types 1–2 on ≥25% of days · types 6–7 on <25%
IBS-D
With diarrhea
Mostly loose, mushy, or liquid stools, often with urgency. Most logs fall into types 6–7.
Types 6–7 on ≥25% of days · types 1–2 on <25%
IBS-M
Mixed pattern
Alternates between hard and loose stools across the same week or month. Both ends of the scale show up.
Types 1–2 and 6–7 each on ≥25% of days
Typical
Well-formed stool
Sausage-shaped, smooth or with small cracks, easy to pass. This is the target range for most people.
Types 3–4
Educational reference only. This is not a diagnosis. Subtypes can shift over time and stool form can vary day to day. If you are unsure of your subtype, consider logging for 14 days and sharing the results with your GP.
Find your own subtype
Log 14 days of Bristol types in GutSpy
One tap per log. See your distribution and your pattern emerge in under two weeks.
Frequently asked
IBS subtypes — FAQ
How do I know which IBS subtype I have?
Log your Bristol stool type for at least 14 days. If ≥25% of your bowel movements are types 1–2, you may align with IBS-C. If ≥25% are types 6–7, IBS-D. If both, IBS-M. This is a clinical framework, not self-diagnosis — confirm with your GP.
Can my subtype change over time?
Yes. IBS subtypes commonly shift across months or years, especially with diet, stress, and treatment changes. Re-logging every few months keeps the picture current.
What if my pattern doesn't fit any subtype?
If fewer than 25% of your stools fall into either extreme, the Rome IV framework calls it IBS-U (unclassified). Talk to your clinician — subtype is just one signal.
Is the Bristol scale really accurate?
For stool form, yes — it is the clinical standard. It doesn't capture frequency, urgency, or pain, which is why a full diary (not just Bristol) is useful.
Sources
- Lewis SJ, Heaton KW. Stool form scale as a useful guide to intestinal transit time. Scand J Gastroenterol. 1997.
- Lacy BE et al. Bowel Disorders (Rome IV). Gastroenterology. 2016.
- American College of Gastroenterology, IBS guidelines. 2021.
Last updated April 2026
Find your own IBS pattern in 14 days
Free forever to log. The insights export is part of IBS Plus.