We‘ve all had times in our lives when our bowel movements weren’t very comfortable. Whether it was the discomfort of having to rush to the bathroom with diarrhea or the straining and abdominal pain that comes from having constipation, many of us know what it feels like to have unusual bowel movements sometimes.
But for some people, diarrhea or constipation can become more common. Many people live with a digestive condition called IBS. This condition can cause symptoms like cramps or bloating. It may also cause constipation, diarrhea, or both. If you have IBS, these symptoms may come and go throughout your life.
Different types of IBS

Studies suggest that between 7–21% of people in the United States may be affected by IBS. This condition shows up differently for each person. This is also the case when it comes to what type of bowel movements you have with IBS. A system called the Rome criteria was developed in 1989 to separate out the different types of IBS.
As per the Rome Foundation, the three different types of IBS (each causing different bowel movements) are:
- IBS with constipation, known as IBS-C
- IBS with diarrhea, known as IBS-D
- IBS with mixed bowel movements (where you get both diarrhea and constipation), known as IBS-M
IBS with constipation (IBS-C)
IBS-C happens when your digestive system is contracting more slowly. These slow contractions mean that it‘s more difficult for food you’ve eaten to move through your digestive tract. This causes constipation, and you‘ll notice infrequent, hard stools that are difficult to pass.
Research from 2017 suggests that around 35% of people with IBS will have IBS-C. On days when you have an irregular bowel movement, IBS-C involves the following, according to the National Institutes of Health (NIH):
- more than a quarter of your stools are lumpy or hard
- less than a quarter of your stools are watery or loose
You may find that your stools are so separated and firm that they look like little pebbles. You may also experience a lot of straining to pass stools, feel that you‘ve not completely cleared your bowels, and feel a lot of urgency to go to the bathroom (known as tenesmus).
Experts say that IBS-C is similar to chronic constipation in that it also involves abdominal pain and discomfort.
IBS with diarrhea (IBS-D)
IBS-D happens when your digestive system contracts more quickly. These fast contractions mean that food moves quickly through your digestive system.
This causes diarrhea and loose, watery stools. You may even notice stools that are entirely liquid or feel a sudden and urgent need to pass stools.
Research suggests that IBS-D may be the most common type of IBS, with around 40% of people with IBS experiencing IBS-D. On days when you have an irregular bowel movement, IBS-D involves the following, according to the NIH:
- more than a quarter of your stools are watery or loose
- less than a quarter of your stools are lumpy or hard
People with IBS-D will also experience other symptoms like abdominal pain, gas, and bloating that come together with loose bowel movements.
IBS with mixed bowel movements (IBS-M)
IBS-M is where food moves through your digestive tract at different speeds. Sometimes, the transit time can be quick, and other times, it can be slow, causing a combination of diarrhea and constipation at different times.
You may experience alternating periods of loose and hard stools or even have both types of stools during the same bowel movement.
IBS-M is the least common type of IBS, with around 23% of people with IBS having IBS-M. On days when you have an irregular bowel movement, IBS-M involves the following, according to the NIH:
- more than a quarter of your stools are watery or loose
- more than a quarter of your stools are lumpy or hard
Many people with IBS will have one common symptom, for example, constipation, but then may find that they suddenly experience another symptom, like diarrhea. This uncertainty and the sudden changes in bowel movements can be difficult to manage and cause stress.