IBS has no biomarker, so trials run on a daily diary: abdominal pain, stool frequency and stool form, averaged by week and compared with a baseline period. Capture puts that diary on the participant's phone and the visit forms at the site in one study. Build and test free, no credit card.
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| Assessment | Screen | Run-in | Rand | Wk 4 | Wk 8 | Wk 12 |
|---|---|---|---|---|---|---|
| Daily abdominal pain (phone) | D | D | D | D | D | |
| Daily stool count and form (phone) | D | D | D | D | D | |
| Symptom severity questionnaire | ||||||
| Global relief or improvement | ||||||
| Safety labs and adverse events |
x = visit form, D = daily diary entries
What an IBS trial needs from its EDC
The study data
IBS is diagnosed on symptoms, using the Rome criteria, so efficacy is measured by what participants report. FDA's 2012 guidance for drugs for IBS with constipation and IBS with diarrhoea recommends daily patient-reported outcomes: abdominal pain intensity and stool frequency or consistency, with weekly averages computed during analysis. The pain responder in that guidance is a reduction of at least 30% from baseline in the weekly average of worst abdominal pain over 24 hours, with additional analyses at greater reductions. For IBS-C, a combined responder requires both pain reduction and an increase in complete spontaneous bowel movements for a set share of treatment weeks. For IBS-D, a stool consistency or frequency component is paired with pain. The guidance itself noted that these definitions were provisional pending qualification of the outcome measures, so confirm current regulator expectations for your region and design in scientific advice.
The data-management consequence is that nearly every number in the primary analysis comes from the diary. Missing days weaken weekly averages; a participant who only fills the diary at the visit produces recall data that undermines the whole design. In Capture the diary is a scheduled daily task opened from a secure link in the phone browser, with reminders by email or SMS and a completion window. The Bristol Stool Scale template shows how stool form is captured as a typed choice rather than free text, and the same pattern covers stool count. The compliance view by site shows who is falling behind during the run-in, when it is still possible to act, and an edit check on the randomisation visit can test the minimum number of valid baseline days.
Symptom severity questionnaires complement the diary at visits. The IBS Symptom Severity Score (IBS-SSS) combines five questions on pain severity, pain frequency, bloating, bowel habit satisfaction and interference with life, for a total of 0 to 500 with conventional cut-offs for mild, moderate and severe disease. It is widely used in academic and dietary or behavioural trials, and in some pharmaceutical programmes as a secondary. Build it as a participant questionnaire and keep its licence terms in your study documents; Capture does not supply instrument wording or verify licences. For related inflammatory conditions see EDC for gastroenterology and IBD trials; IBS has no objective biomarker and no endoscopic endpoint, so the data model is simpler and the diary matters more.
Subtype is usually set at screening from stool form during an observation period (for example, the proportion of abnormal stools being hard or loose), so build the subtype as a derived field from the baseline diary rather than a free choice. Rescue medication, such as a laxative in IBS-C or an antidiarrhoeal in IBS-D, is normally restricted or counted as an intercurrent event, so record every use with a date. The concomitant medications template handles background therapy such as fibre or probiotics, which sponsors often need to keep stable.
Valid diary days (median)
12 / 14
Below the 10-day minimum
5
Not yet randomised
23
Reminders not working?
Protocol to build
| Protocol element | What the data looks like | Where it lives in Capture |
|---|---|---|
| Diagnosis and subtype | Rome criteria met, subtype from baseline stool form | Eligibility screening template; derived field |
| Daily abdominal pain | 0 to 10 entry each day, weekly mean | Phone diary; NPRS layout |
| Stool count and form | Number of stools, Bristol type per stool | Bristol Stool Scale template |
| Run-in completeness | Minimum valid days before randomisation | Edit check on the randomisation visit |
| Symptom severity | Five items, total score | Participant questionnaire at visits; licence per rights holder |
| Global relief or improvement | Weekly or visit-based rating | Participant questionnaire |
| Rescue and background therapy | Laxative or antidiarrhoeal use, fibre, probiotics | Concomitant medications template |
| Safety | Constipation or diarrhoea events, ischaemic colitis in some classes | Adverse event form |
Licensed instruments stay with your study documents. Capture does not supply or verify instrument licences; licence controls exist only on participant questionnaires.
Upload the protocol, let the AI draft visits and forms for you to review, and test with sample data. Free sandbox, no credit card.
Design details
Not every IBS trial is a drug trial. Dietary interventions, gut-directed hypnotherapy, cognitive behavioural programmes and digital therapeutics are common, and they change what is collected: adherence, intervention engagement, food records and psychological measures such as anxiety or depression. The food diary template and HADS or GAD-7 pages show the typical structures. Blinding is harder in these designs, so describe in the protocol which outcomes are participant-reported and how assessors stay blinded.
Drug trials commonly run 12 weeks of treatment, sometimes with a 4-week randomised withdrawal or follow-up. Build each as an epoch. Safety attention goes to bowel-related adverse events: constipation, diarrhoea and, in some classes, serious bowel events that need prompt reporting. See adverse event reporting software.
IBS studies are often large, with many sites, because effect sizes are modest. QR-code enrolment, site-level participant numbering and a separate site coordinator portal keep sites organised, and the compliance view by site makes diary slippage visible. See multi-site clinical trial management, Phase 3 EDC and epro compliance reminders.
Build sequence
A practical order of work.
Upload the protocol (PDF, DOCX or DOC) and let the AI study builder propose the schedule and forms. Nothing is saved until a person reviews it.
A daily task with pain, stool count and stool form, reminders and a completion window.
An edit check on the number of valid baseline days and the derived subtype.
Symptom severity and global relief at the visits your protocol sets.
Run practice participants through run-in, randomisation and treatment, deliberately missing diary days.
Approved forms lock for live use. Real participants start the paid live phase.
Before first participant
Diary items, symptom scores and diagnostic criteria under their rights holders' terms, filed in the study documents.
Minimum diary days for baseline and for each treatment week.
How baseline stool form sets IBS-C, IBS-D or mixed.
Permitted rescue medication and how use is counted.
Timing and escalation for missed days.
CSV or Excel with the data dictionary opened in the statistics package.
Yes. A daily task with a 0 to 10 pain question, stool count and Bristol form choice opens from a secure link in the phone browser, with reminders by email or SMS and a completion window. No app is needed.
Capture stores every daily entry and exports it with a data dictionary so your statistician can derive weekly means and responder flags. Simple derived fields can be built as calculated fields.
Yes, with an edit check on the randomisation visit using the rule you define. It raises an automatic query.
Not yet as a dedicated template page. You can build the questionnaire from your licensed source as a participant questionnaire; licences stay with your study documents and Capture does not supply or verify them.
Yes. Food diaries, adherence forms and psychological measures are built as forms and tasks in the same study as the symptom diary.
Yes. Capture is suitable for Phase 1, 2 and 3 studies, with site-level numbering, a site coordinator portal and by-site exports.
The sandbox is free with every feature, no credit card and no time limit. You pay only once you go live with real participants. Pricing is not published on the site, so ask for terms for your study.
Free sandbox with every feature. No credit card, and you pay only when you go live.