NCT07569419

Brief Summary

Linaclotide is a medicine used to treat constipation and irritable bowel syndrome with constipation (IBS-C). It works by acting on the surface of the gut lining, where it increases the movement of salt and water into the bowel. This softens stools, makes them easier to pass, and can also reduce gut pain One advantage of linaclotide is that, unlike some natural substances in the gut, it is stable and can act throughout the intestine. Studies in animals show that it has the strongest effect in the upper small intestine, but it may act in other parts of the bowel as well. In people, however, it is not yet clear whether linaclotide mainly works in the small intestine or in the large intestine (colon). Knowing this is important, because it could help the investigators understand whether linaclotide might also be useful in other conditions, such as cystic fibrosis, where the gut does not handle fluid properly. Linaclotide is taken as a capsule, but less than 1% is absorbed into the bloodstream. Instead, it stays in the gut, where it is broken down into smaller active parts. This means both the small intestine and colon may be exposed to its effects. Until now, it has been hard to study this because traditional methods only measure one part of the gut at a time. A team at the University of Nottingham has developed MRI scanning methods that can safely and non-invasively measure water content in the small intestine and colon. The aim of this pilot study is to use MRI in healthy volunteers to see exactly where linaclotide acts. This knowledge will help optimise future studies in conditions such as cystic fibrosis.

Trial Health

77
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
26

participants targeted

Target at P25-P50 for early_phase_1

Timeline
5mo left

Started Mar 2026

Shorter than P25 for early_phase_1

Geographic Reach
1 country

1 active site

Status
recruiting

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Progress29%
Mar 2026Oct 2026

First Submitted

Initial submission to the registry

December 15, 2025

Completed
3 months until next milestone

Study Start

First participant enrolled

March 9, 2026

Completed
2 months until next milestone

First Posted

Study publicly available on registry

May 6, 2026

Completed
3 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

August 1, 2026

Expected
2 months until next milestone

Study Completion

Last participant's last visit for all outcomes

October 1, 2026

Last Updated

May 6, 2026

Status Verified

April 1, 2026

Enrollment Period

5 months

First QC Date

December 15, 2025

Last Update Submit

April 28, 2026

Conditions

Keywords

linaclotidecystic fibrosisgastrointestinalMRI

Outcome Measures

Primary Outcomes (1)

  • Small bowel water content

    Area under curve (AUC) 0-360 minutes Water content in small bowel as assessed by MRI (mL)

    Baseline, and 0, 60, 120, 180, 240, 300, 360 minutes post-dose

Secondary Outcomes (7)

  • Colon water content

    Baseline, and 0, 60, 120, 180, 240, 300, 360 minutes post-dose

  • Colonic regional segmental volumes

    Baseline, and 0, 60, 120, 180, 240, 300, 360 minutes post-dose

  • Changes in stool consistency

    2 days before intervention, 5 days post-intervention

  • Changes in whole gut transit time (WGTT)

    1 day post-intervention

  • Gastrointestinal symptom rating

    2 days pre-intervention and 5 days post-intervention

  • +2 more secondary outcomes

Study Arms (2)

Linaclotide

EXPERIMENTAL

290 mcg linaclotide across 2 days

Drug: Linaclotide 290 micrograms

Placebo

PLACEBO COMPARATOR

Lactose placebo

Drug: Lactose placebo pill

Interventions

290 mcg, 2 days dosing, oral capsule form

Linaclotide

Placebo form, oral capsules identical to linaclotide

Placebo

Eligibility Criteria

Age18 Years - 65 Years
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)

You may qualify if:

  • Participant is willing and able to give informed consent for participation in the study
  • Not currently taking any medications (except for selective serotonin reuptake inhibitors, low dose tricyclic antidepressants, antihistamines, and oral contraceptive pill).
  • Aged between 18-60 years.
  • Ability to conform to the study protocol, including overnight fasting, dietary and lifestyle restriction, administering linaclotide and placebo intervention, MRI scanning, consuming the rice pudding/blue dye meal, and rating stool frequency and appearance.

You may not qualify if:

  • Contraindication to MRI scanning (i.e. metallic implants, pacemakers, history of metallic foreign body in eye(s) and penetrating eye injury, unable to lie flat and relatively still for less than 5 minutes.)
  • Pregnancy, lactating, or planning pregnancy during the investigation declared by candidate.
  • History declared by the candidate of pre-existing gastrointestinal disorder that may affect bowel function.
  • Reported history of previous resection of the oesophagus, stomach, or intestine (excluding appendix).
  • Intestinal stoma.
  • Any medical condition that may potentially compromise participation in the study e.g., known food intolerance to rice pudding, known contraindication to the oral administration of linaclotide or placebo.
  • Has a body mass index (BMI) value less than 18.5 or greater than 35.
  • Will not agree to follow dietary and lifestyle restrictions required.
  • Unable to stop drugs known to alter GI motility including mebeverine, opiates, monoamine oxidase inhibitors, phenothiazines, benzodiazepines, calcium channel antagonists for the duration of the study.
  • Participants who are currently (or in the past 3 months) taking antibiotics or probiotics as these may impact GI function.
  • Participation in night shift work the week prior to the study day. Night work is defined as working between midnight and 6.00 AM.
  • Anyone who in the opinion of the investigator is unlikely to be able to comply with the protocol e.g., cognitive dysfunction, chaotic lifestyle related to substance abuse.
  • Having taken part in a research study in the last 3 months involving invasive procedures or an inconvenience allowance

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Sir Peter Mansfield Imaging Centre

Nottingham, NG7 2QX, United Kingdom

RECRUITING

Related Publications (19)

  • Wilkinson-Smith, V., Hoad, C., Atkinson, D., Marciani, L., Corsetti, M., Scott, S. M., Taylor, S., Gowland, P., & Spiller, R. (2021). O59 MRI methods to define colonic function in health and constipation. Gut, 70(Suppl 1), A32-A33. https://doi.org/10.1136/GUTJNL-2020-BSGCAMPUS.59

    BACKGROUND
  • Stefano, M. A., Sandy, N. S., Zagoya, C., Duckstein, F., Ribeiro, A. F., Mainz, J. G., & Lomazi, E. A. (2022). Diagnosing constipation in patients with cystic fibrosis applying ESPGHAN criteria. Journal of Cystic Fibrosis, 21(3), 497-501. https://doi.org/10.1016/j.jcf.2021.08.021

    BACKGROUND
  • Stefano, M. A., Poderoso, R. E., Mainz, J. G., Ribeiro, J. D., Ribeiro, A. F., & Lomazi, E. A. (2020). Prevalence of constipation in cystic fibrosis patients: a systematic review of observational studies. Jornal de Pediatria, 96(6), 686-692. https://doi.org/10.1016/j.jped.2020.03.004

    BACKGROUND
  • Rubinstein, S., Moss, R., & Lewiston, N. (1986). Constipation and Meconium Ileus Equivalent in Patients With Cystic Fibrosis. Pediatrics, 78(3), 473-479. https://doi.org/10.1542/PEDS.78.3.473

    BACKGROUND
  • McHugh, D. R., Cotton, C. U., Moss, F. J., Vitko, M., Valerio, D. M., Kelley, T. J., Hao, S., Jafri, A., Drumm, M. L., Boron, W. F., Stern, R. C., McBennett, K., & Hodges, C. A. (2018). Linaclotide improves gastrointestinal transit in cystic fibrosis mice by inhibiting sodium/hydrogen exchanger 3. American Journal of Physiology - Gastrointestinal and Liver Physiology, 315(5), G868. https://doi.org/10.1152/AJPGI.00261.2017

    BACKGROUND
  • arciani, L., Wright, J., Foley, S., Hoad, C. L., Totman, J. J., Bush, D., Hartley, C., Armstrong, A., Manby, P., Blackshaw, E., Perkins, A. C., Gowland, P. A., & Spiller, R. C. (2010). Effects of a 5-HT(3) antagonist, ondansetron, on fasting and postprandial small bowel water content assessed by magnetic resonance imaging. Alimentary Pharmacology & Therapeutics, 32(5), 655-663. https://doi.org/10.1111/J.1365-2036.2010.04395.X

    BACKGROUND
  • Marciani, L., Garsed, K. C., Hoad, C. L., Fields, A., Fordham, I., Pritchard, S. E., Placidi, E., Murray, K., Chaddock, G., Costigan, C., Lam, C., Jalanka-Tuovinen, J., De Vos, W. M., Gowland, P. A., & Spiller, R. C. (2014). Stimulation of colonic motility by oral PEG electrolyte bowel preparation assessed by MRI: comparison of split vs single dose. Neurogastroenterology and Motility, 26(10), 1426-1436. https://doi.org/10.1111/NMO.12403

    BACKGROUND
  • Luo, M., Liu, Y., Nikolovska, K., Riederer, B., Patrucco, E., Hofmann, F., & Seidler, U. (2024). cGMP-dependent kinase 2, Na+/H+ exchanger NHE3, and PDZ-adaptor NHERF2 co-assemble in apical membrane microdomains. Acta Physiologica, 240(4), e14125. https://doi.org/10.1111/APHA.14125

    BACKGROUND
  • Hayee, B., Watson, K. L., Campbell, S., Simpson, A., Farrell, E., Hutchings, P., Macedo, P., Perrin, F., Whelan, K., & Elston, C. (2019). A high prevalence of chronic gastrointestinal symptoms in adults with cystic fibrosis is detected using tools already validated in other GI disorders. United European Gastroenterology Journal, 7(7), 881-888. https://doi.org/10.1177/2050640619841545

    BACKGROUND
  • Hannig, G., Tchernychev, B., Kurtz, C. B., Bryant, A. P., Currie, M. G., & Silos-Santiago, I. (2014). Guanylate cyclase-C/cGMP: an emerging pathway in the regulation of visceral pain. Frontiers in Molecular Neuroscience, 7(1 APR), 31. https://doi.org/10.3389/FNMOL.2014.00031

    BACKGROUND
  • Ford, A. C., & Suares, N. C. (2011). Effect of laxatives and pharmacological therapies in chronic idiopathic constipation: systematic review and meta-analysis. Gut, 60(2), 209-218. https://doi.org/10.1136/GUT.2010.227132

    BACKGROUND
  • Dellschaft, N., Murray, K., Ren, Y., Marciani, L., Gowland, P., Spiller, R., & Hoad, C. (2025). Assessing Water Content of the Human Colonic Chyme Using the MRI Parameter T1: A Key Biomarker of Colonic Function. Neurogastroenterology and Motility, 37(4). https://doi.org/10.1111/NMO.14999

    BACKGROUND
  • Dellschaft, N., Hoad, C., Marciani, L., Gowland, P., & Spiller, R. (2022). Small bowel water content assessed by MRI in health and disease: a collation of single-centre studies. Alimentary Pharmacology & Therapeutics, 55(3), 327-338. https://doi.org/10.1111/APT.16673

    BACKGROUND
  • e Lisle, R. C., & Borowitz, D. (2013). The Cystic Fibrosis Intestine. Cold Spring Harbor Perspectives in Medicine, 3(9), a009753. https://doi.org/10.1101/CSHPERSPECT.A009753

    BACKGROUND
  • Corsetti, M., & Tack, J. (2013). Linaclotide: A new drug for the treatment of chronic constipation and irritable bowel syndrome with constipation. United European Gastroenterology Journal, 1(1), 7-20. https://doi.org/10.1177/2050640612474446

    BACKGROUND
  • Busby, R. W., Kessler, M. M., Bartolini, W. P., Bryant, A. P., Hannig, G., Higgins, C. S., Solinga, R. M., Tobin, J. V., Wakefield, J. D., Kurtz, C. B., & Currie, M. G. (2013). Pharmacologic Properties, Metabolism, and Disposition of Linaclotide, a Novel Therapeutic Peptide Approved for the Treatment of Irritable Bowel Syndrome with Constipation and Chronic Idiopathic Constipation. The Journal of Pharmacology and Experimental Therapeutics, 344(1), 196-206. https://doi.org/10.1124/JPET.112.199430

    BACKGROUND
  • Bryant, A. P., Busby, R. W., Bartolini, W. P., Cordero, E. A., Hannig, G., Kessler, M. M., Pierce, C. M., Solinga, R. M., Tobin, J. V., Mahajan-Miklos, S., Cohen, M. B., Kurtz, C. B., & Currie, M. G. (2010). Linaclotide is a potent and selective guanylate cyclase C agonist that elicits pharmacological effects locally in the gastrointestinal tract. Life Sciences, 86(19-20), 760-765. https://doi.org/10.1016/J.LFS.2010.03.015

    BACKGROUND
  • Atluri, D. K., Chandar, A. K., Bharucha, A. E., & Falck-Ytter, Y. (2014). Effect of linaclotide in irritable bowel syndrome with constipation (IBS-C): a systematic review and meta-analysis. Neurogastroenterology and Motility, 26(4), 499-509. https://doi.org/10.1111/NMO.12292

    BACKGROUND
  • Aliyu, A., Dellschaft, N., Hoad, C., Williams, H., Gaudoin, E., Sulaiman, S., Crooks, C., Gowland, P., Aran, A., Lange, R., Bois De Fer, B., Corsetti, M., Marciani, L., & Spiller, R. (2025). Magnetic Resonance Imaging Reveals Novel Insights into the Dual Mode of Action of Bisacodyl: A Randomized, Placebo-controlled Trial in Constipation. Clinical Pharmacology and Therapeutics, 117(5), 1284-1291. https://doi.org/10.1002/CPT.3532

    BACKGROUND

MeSH Terms

Conditions

Cystic Fibrosis

Condition Hierarchy (Ancestors)

Pancreatic DiseasesDigestive System DiseasesLung DiseasesRespiratory Tract DiseasesGenetic Diseases, InbornCongenital, Hereditary, and Neonatal Diseases and AbnormalitiesInfant, Newborn, Diseases

Central Study Contacts

Study Design

Study Type
interventional
Phase
early phase 1
Allocation
RANDOMIZED
Masking
TRIPLE
Who Masked
PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
Purpose
TREATMENT
Intervention Model
CROSSOVER
Sponsor Type
OTHER
Responsible Party
PRINCIPAL INVESTIGATOR
PI Title
Professor Robin Spiller

Study Record Dates

First Submitted

December 15, 2025

First Posted

May 6, 2026

Study Start

March 9, 2026

Primary Completion (Estimated)

August 1, 2026

Study Completion (Estimated)

October 1, 2026

Last Updated

May 6, 2026

Record last verified: 2026-04

Locations