IBS Subtype Quiz

What the four IBS subtypes are

Irritable bowel syndrome is not one pattern. Clinicians classify it by what your stools look like on the days your bowel habits are abnormal, using the Bristol Stool Scale. If more than a quarter of those bowel movements are hard and lumpy (Bristol types 1–2) and fewer than a quarter are loose or watery (types 6–7), that is IBS-C, constipation-predominant. The reverse is IBS-D, diarrhea-predominant. If both hard and loose stools each make up more than a quarter, that is IBS-M, mixed. When symptoms meet IBS criteria but fit none of those patterns, it is IBS-U, unclassified.

This quiz asks 10 questions about how often you have hard versus loose stools, your main symptom during a flare, incomplete emptying, how soon symptoms follow a meal, which foods worsen them, pain location, how long you have had symptoms and how a typical week looks. It scores constipation and diarrhea signals separately and then reports the subtype your answers most closely match.

Why your subtype changes what helps

Diet advice that helps one subtype can make another worse. Soluble fiber such as psyllium tends to help IBS-C, while large amounts of insoluble fiber (wheat bran) can worsen bloating. For IBS-D, caffeine, sugar alcohols like sorbitol and large fatty meals are frequent culprits, and symptoms often start soon after eating. Many people in every subtype benefit from a structured low-FODMAP trial, but the foods that turn out to be personal triggers differ from person to person.

That is why identifying your subtype is a useful first step before you start testing foods: it tells you which patterns to look for and which common advice to be cautious about.

What this quiz cannot tell you

It is a self-assessment, not a diagnosis. IBS is diagnosed by a clinician after ruling out other conditions. See a doctor promptly if you notice blood in your stool, unexplained weight loss, symptoms that wake you at night, persistent vomiting, anemia, or a family history of inflammatory bowel disease, celiac disease or colorectal cancer, or if symptoms begin after age 50. Subtypes can also shift over months or years, so treat your result as a snapshot.

How do I know which IBS subtype I have?

Doctors use the Bristol Stool Scale: on days with abnormal bowel movements, if more than 25% are hard and lumpy and fewer than 25% are loose, it is IBS-C; the reverse is IBS-D; both more than 25% is IBS-M. Tracking your stool form for two to four weeks gives a more reliable answer than memory, and this quiz gives you a first estimate.

Can my IBS subtype change over time?

Yes. Studies following people with IBS over several years find that a large share move between subtypes, particularly between IBS-M and the other two. Stress, diet, infections, medications and hormonal changes can all shift the pattern, so retake the quiz if your symptoms change.

Is the IBS subtype quiz a diagnosis?

No. It is an educational self-assessment that helps you describe your pattern. Only a clinician can diagnose IBS, because other conditions such as celiac disease, inflammatory bowel disease and thyroid problems can look similar and need to be ruled out.

What should I do after I find my subtype?

Start logging meals, symptoms and stool form together, because IBS reactions are often delayed by several hours to a couple of days. After a few weeks the foods that repeatedly precede your worst days usually stand out. Discuss the results, and any structured elimination diet, with a doctor or registered dietitian.