Gastroenterology · Phase 3
Linaclotide: constipation Trial 303
What was tested?
Linaclotide versus placebo in adults with chronic constipation. ↗
Registered primary question: The proportion with at least three complete spontaneous bowel movements per week and at least one more than baseline, for at least nine of twelve weeks. ↗
What the reviewed report found
Journal year 2011 · Article summary reviewed 2026-09-20
The primary bowel-response endpoint was reached by 21.2% and 19.4% in the two active groups, compared with 3.3% with placebo.↗
Keep in context: The registry identifies protocol MCP-103-303 and 643 enrolled participants. Only Trial 303 outcomes from the two-trial paper are shown here; the paper’s total of 1,276 covers both trials. ↗↗
Participants, design, limitations and sources
Registry snapshot
- Registry enrollment
- 643 · reported actual
- Registry status
- Completed
- Allocation and masking
- Randomized · Quadruple
- Design
- Parallel
- Eligible ages
- 18 Years; maximum not specified
- Registry results
- Posted in this snapshot
Registry source ↗ · Updated 2013-01-30; retrieved 2026-09-20. Registry enrollment is not necessarily the analyzed sample in a publication. Posted registry results and published article results are separate.
Adult chronic constipation: Trial 303
- Design in the report
- A randomized, double-blind, placebo-controlled 12-week trial tested two active groups.↗
- Participants in the report
- Adults with chronic constipation participated; the abstract reports 1,276 participants across Trials 303 and 01 together, without a separate Trial 303 count.↗
- Limitations
- These are the Trial 303 efficacy results. The abstract’s 4.2% diarrhea-related discontinuation figure is reported across active groups in the two-trial publication and is not a separately appraised Trial 303 safety estimate. Follow-up was 12 weeks.↗
This reading covers the article abstract and record metadata. Read its preserved Human Evidence Review →
How the study identity and sources were checked
Study context checked 2026-09-20. Existing article summaries keep their original review dates. This is a selected study reading, not a complete literature or full-text appraisal.
Registry
Trial of Linaclotide in Patients With Chronic Constipation ↗
Protocol identifier: MCP-103-303. Sponsor: Ironwood Pharmaceuticals, Inc..
Retrieved 2026-09-20; SHA-256 c670ef245ce9b9e39f402d6cc3bea1c86cbabf40980fc409f1c0a81ecdcca7fa.
PMID 21830967
Two randomized trials of linaclotide for chronic constipation. ↗
Exact trial identity is declared in PubMed’s ClinicalTrials.gov databank field. The registry independently labels this reference DERIVED. These source labels do not establish that every result in a paper applies to this trial.
Identity metadata retrieved 2026-09-20. EFetch XML; locate MedlineCitation/PMID 21830967. SHA-256 24d773849646882ab3031eef6fc3481ce604a26f409a13a58e22a2004aca0a3b.
Scientific summary uses the original 2026-09-20 source snapshot: SHA-256 24d773849646882ab3031eef6fc3481ce604a26f409a13a58e22a2004aca0a3b.