 BOSTON--BUSINESS WIRE--Ironwood Pharmaceuticals, Inc. Nasdaq: IRWD, a GI-focused healthcare company, today provided an update on its fourth quarter and full year 2020 results and recent business performance. The fourth quarter marked a strong finish to 2020, which is a testament to the hard work and dedication of the Ironwood team. LINZESS U.S. net sales grew 10 year-over-year in 2020 remarkable growth in the face of the COVID-19 pandemic and Ironwood delivered its second full year of 