The study is a multi-centre, observational study which enrolls 150 IBS-C patients and 150 non-IBS-C patients in China.

The potential study subject will be identified by the investigators by face-to-face visit, and there will be only 1 visit in this study. Every patient will complete both ROME IV and the Simplified Diagnosis Tool during the visit, and in the same day.

The study will collect results of the ROME IV and the Simplified Diagnosis Tool. Sensitivity and specificity of simplified diagnosis methodology compared with ROME IV will be analysed after all the data has been collected.

Inclusion Criteria:

Group 1 (IBS-C)

• ≥18 years old
• Decrease of frequency of bowel movement (<3 time per week), change of stool consistency (stool that is hard and difficult to pass, Bristol Types 1 to 3), or other 'constipation symptoms' judged by investigators.
• With abdominal symptoms such as abdominal pain, bloating, and abdominal discomfort, or other 'constipation symptoms' judged by investigators.
• Result of ROME VI marked as 'IBS-C'.

Group 2 (non-IBS-C)

• ≥18 years old
• Decrease of frequency of bowel movement (<3 time per week), change of stool consistency (stool that is hard and difficult to pass, Bristol Types 1 to 3), or other 'constipation symptoms' judged by investigators.
• With abdominal symptoms such as abdominal pain, bloating, and abdominal discomfort, or other 'constipation symptoms' judged by investigators.
• Result of ROME VI marked as 'Non IBS-C'.

Exclusion Criteria:

• Individuals with a cognitive condition and unable to finish the questionnaire.

• Individuals have an acute or chronic non-GI condition that can be associated with constipation; e.g., central nervous system cause (Parkinson's disease, spinal cord injury, and multiple sclerosis), pseudo-obstruction, colonic inertia, megacolon, megarectum, bowel obstruction, descending perineum syndrome, solitary rectal ulcer syndrome, systemic sclerosis.

• Individuals who had been diagnosed with the following organic health problems likely to affect GI symptoms:

  • Inflammatory bowel disease (Crohn's disease or ulcerative colitis)
  • cancer anywhere in the GI tract or current infection of the GI tract.
  • Pelvic floor dysfunction. (i.e., disease that is not adequately treated or stable with therapy.)
  • Any history of colon surgeries.

• Individuals who participate in any interventional study currently.

• Not suitable for the study judged by investigators.

With the ratio of IBS-C/non-IBS-C as 1:1, when the sample size is 300, assuming the sensitivity and specificity using ROME IV as reference are 0.85 and 0.85 respectively, a two-sided 95% confidence interval will produce confidence interval widths of 0.12 and 0.12 respectively.

In addition, with the same assumption as above, a total sample size of 300 (which includes 150 subjects with the IBS-C) achieves 99% power to detect a change in sensitivity/ specificity from 0.7 to 0.85 using a two-sided binomial test. The target significance level is 0.05.

Qualified researchers can request access to anonymized individual patient-level data from AstraZeneca group of companies sponsored clinical trials via the request portal. All request will be evaluated as per the AZ disclosure commitment: https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.

AstraZeneca will meet or exceed data availability as per the commitments made to the EFPIA Pharma Data Sharing Principles. For details of our timelines, please rerefer to our disclosure commitment at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure

When a request has been approved AstraZeneca will provide access to the de-identified individual patient-level data in an approved sponsored tool . Signed Data Sharing Agreement (non-negotiable contract for data accessors) must be in place before accessing requested information. Additionally, all users will need to accept the terms and conditions of the SAS MSE to gain access. For additional details, please review the Disclosure Statements at https://astrazenecagrouptrials.pharmacm.com/ST/Submission/Disclosure.