A 12-week, randomized, controlled trial with a 4-week randomized withdrawal period to evaluate the efficacy and safety of linaclotide in irritable bowel syndrome with constipation.

"Guarantor of the article: Jeffrey M. Johnston, MD.: Specific author contributions: Wrote the initial draft of the manuscript, assisted in the interpretation of data, and provided critical revision: Satish Rao and Anthony J. Lembo; designed the trial: Jeffrey M. Johnston, Bernard J. Lavins, Harvey A. Schneier, and Steven J. Shiff; assisted in the interpretation of data and critical revision of the manuscript for important intellectual content: Jeffrey M. Johnston, Bernard J. Lavins, Caroline B. Kurtz, Mark G. Currie, Harvey A. Schneier, and Steven J. Shiff; provided statistical design, analyses, and interpretation: James E. MacDougall, Xinwei D. Jia, Kelvin Shi, and James Z. Shao; coordinated acquisition of data and trial supervision: Paul Eng and Susan M. Fox.: Financial support: This trial was funded by Forest Research Institute and Ironwood Pharmaceuticals, Inc.: Potential competing interests: Jeffrey M. Johnston, Caroline B. Kurtz, James E. MacDougall, James Z. Shao, Bernard J. Lavins, and Mark G. Currie are employees of Ironwood Pharmaceuticals and own stock/stock options in Ironwood Pharmaceuticals. Harvey A. Schneier, Steven J. Shiff, Paul Eng, Susan M. Fox, Xinwei D. Jia, and Kelvin Shi are employees of Forest Laboratories and own stock/stock options in Forest Laboratories. Anthony J. Lembo and Satish Rao are paid consultants to Ironwood Pharmaceuticals and Forest Research Institute."

"Financial support: This trial was funded by Forest Research Institute and Ironwood Pharmaceuticals, Inc."