Summary
Caffeine has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Irritable Bowel Syndrome (IBS) would be drug repurposing rather than first-in-human development. This does not mean it is approved for Irritable Bowel Syndrome (IBS). ClinicalTrials.gov lists 8 registered trials linking Caffeine to Irritable Bowel Syndrome (IBS): 2 are active or not yet recruiting; 6 have completed. None of the registered studies carries a drug-development phase label, which is typical for behavioural, device and supplement protocols. It plans or enrolled 139 participants. Registration activity spans 2015 to 2026. The literature layer holds 6 publications for this pair: 2 Cochrane reviews and 4 clinical trial publications. Publication years run from 2015 to 2024. Because at least one synthesis-level source exists (systematic review, meta-analysis or Cochrane review), this pair has been assessed beyond single studies, although the synthesis may concern a different indication.
The RepurpOS disease-intelligence file for Irritable Bowel Syndrome ranks 228 candidate therapeutics from Open Targets, ChEMBL, DGIdb and PubMed; only a minority carry direct clinical evidence, and this page covers one of those. Spontaneous remission context recorded for the condition: IBS is chronic and remitting; spontaneous 'remission' (symptom resolution without treatment) in ~30-40% at 2 years but symptom recurrence common; 10-20% develop persistent daily symptoms; <10% achieve permanent remission.
Evidence table
| Evidence tier | A · Strong |
|---|---|
| Evidence score | 57.0 (trials 19.0, literature 18.0, tier 15, approved bonus 5.0) |
| Registered trials | 8 total: 0 recruiting, 2 active / not yet recruiting, 6 completed, 0 other |
| Linked publications | 6 (4 clinical trial publications, 2 Cochrane reviews) |
| Agent type | Drug (Small molecule) |
| Development stage (any indication) | Approved |
| Mechanism / class | inhibitor; inhibitor |
| Data sources | DGIdb |
| Linked via biomarker / target | ADORA2A |
How the evidence score is calculated
- Each registered trial scores by status (recruiting / active / enrolling 3, completed 2.5, not yet recruiting 2, unknown 1, terminated / withdrawn / suspended 0.5) plus a phase bonus (phase 3-4 +2, phase 2 +1, phase 1 +0.5). The trial component is capped at 30.
- Each literature item scores by design (Cochrane review 5, meta-analysis 4, systematic review 3, RCT 3, clinical trial publication 2, curated reference 1.5, other PubMed record 1). The literature component is capped at 30.
- The existing evidence tier adds 15 (A / Strong), 10 (B / Moderate), 5 (C / Preliminary) or 0 (D / Anecdotal).
- Agents approved for any indication (max clinical phase 4) add 5, because an approved agent has an established safety profile that lowers the barrier to repurposing trials.
- The score ranks what has been studied, not what works. It does not read effect sizes or directions of effect.
Registered clinical trials
| NCT ID | Title | Status | Phase | Enrolment |
|---|---|---|---|---|
| NCT02450370 | Diets in Symptom Relief and the Influence of Quality of Life in People With Irritable Bowel Syndrome 2015 | completed | Not applicable | 103 |
| NCT07052890 | Curcumin, Vitamin D and Green Tea in IBS-D 2024 | completed | Not applicable | 78 |
| NCT05985018 | Traditional Dietary Advice Vs. Mediterranean Diet in IBS 2023 | completed | Not applicable | 139 |
| NCT03423069 | Low FODMAPs Diet vs. Specific Dietary Advice in Patients With IBS Diarrheal Variant 2018 | completed | Not applicable | 62 |
| NCT05307185 | Tritordeum-based Foods for IBS Symptoms 2022 | completed | Not applicable | 135 |
| NCT05832801 | Effect of Pilates Exercises on Patients With Irritable Bowel Syndrome 2023 | completed | Not applicable | 60 |
| NCT07560345 | Effect of Neurodynamic Mobilization of Vagus Nerve on Irritable Bowel Syndrome in Women 2026 | not yet recruiting | Not applicable | 32 |
| NCT07533500 | Effect of Autogenic Relaxation Training on Irritable Bowel Syndrome In Adult Females 2026 | not yet recruiting | Not applicable | 44 |
Published literature
- Clinical trial publication Randomized trial in postprandial functional dyspepsia: Reassurance and diagnostic explanation with or without traditional dietary adviceBuckle RL, Brown LC, Aziz I · Neurogastroenterology and motility · 2024 · PMID 38178367
- Cochrane review Examining the Association between Coffee Intake and the Risk of Developing Irritable Bowel Syndrome: A Systematic Review and Meta-AnalysisLee JY, Yau CY, Loh CYL et al. · Nutrients · 2023 · PMID 38004138
- Clinical trial publication Herbal formula improves upper and lower gastrointestinal symptoms and gut health in Australian adults with digestive disordersRied K, Travica N, Dorairaj R et al. · Nutrition research (New York, N.Y.) · 2020 · PMID 32151878
- Clinical trial publication The Impact of a 4-Week Low-FODMAP and mNICE Diet on Nutrient Intake in a Sample of US Adults with Irritable Bowel Syndrome with DiarrheaEswaran S, Dolan RD, Ball SC et al. · Journal of the Academy of Nutrition and Dietetics · 2020 · PMID 31103370
- Cochrane review British Dietetic Association systematic review and evidence-based practice guidelines for the dietary management of irritable bowel syndrome in adults (2016 update)McKenzie YA, Bowyer RK, Leach H et al. · Journal of human nutrition and dietetics : the official journal of the British Dietetic Association · 2016 · PMID 27272325
- Clinical trial publication Diet low in FODMAPs reduces symptoms of irritable bowel syndrome as well as traditional dietary advice: a randomized controlled trialBöhn L, Störsrud S, Liljebo T et al. · Gastroenterology · 2015 · PMID 26255043
Mechanism and notes
Recorded mechanism or class: inhibitor; inhibitor.
OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in DGIdb, in this case via the biomarker or target ADORA2A. The tier describes how well the drug-disease link is documented, not how well the drug works.
Frequently asked questions
Is Caffeine approved for Irritable Bowel Syndrome (IBS)?
Caffeine has reached the approved stage (maximum clinical phase 4) for at least one indication, so its use in Irritable Bowel Syndrome (IBS) would be drug repurposing rather than first-in-human development. This does not mean it is approved for Irritable Bowel Syndrome (IBS). Approval status for the specific indication should always be confirmed with the relevant regulator and prescribing information.
Is Caffeine in clinical trials for Irritable Bowel Syndrome (IBS)?
ClinicalTrials.gov lists 8 registered trials linking Caffeine to Irritable Bowel Syndrome (IBS): 2 are active or not yet recruiting; 6 have completed. None of the registered studies carries a drug-development phase label, which is typical for behavioural, device and supplement protocols. It plans or enrolled 139 participants. Registration activity spans 2015 to 2026.
What does the evidence show for Caffeine in Irritable Bowel Syndrome (IBS)?
Caffeine has both completed registered trials and synthesis-level publications linked to Irritable Bowel Syndrome (IBS). That is the strongest profile in this database, but the summaries here do not extract effect sizes, so read the linked reviews for direction and magnitude of benefit. OSMF's existing evidence tier for this pair is A (Strong), derived from the strength of the disease association recorded in DGIdb, in this case via the biomarker or target ADORA2A. The tier describes how well the drug-disease link is documented, not how well the drug works.
Cite this page
Data: ClinicalTrials.gov, PubMed, Open Targets, ChEMBL, DGIdb and the OSMF therapeutic agent database. Last updated 2026-07-05. Page built 2026-10-07.