Ironwood Pharmaceuticals is a specialty biotech focused on GI and rare diseases. Its core commercial asset is LINZESS (linaclotide), a once-daily prescription pill for irritable bowel syndrome with constipation (IBS-C), chronic idiopathic constipation (CIC), and functional constipation in pediatric patients. LINZESS works by activating GC-C receptors in the gut to accelerate bowel function and reduce abdominal pain, and holds roughly 45% U.S. prescription market share in its category. Ironwood co-commercializes LINZESS with AbbVie in the U.S., splitting net profits equally, which makes Ironwood's revenue a function of net sales, gross-to-net dynamics, and shared selling costs rather than a simple royalty. Outside the U.S., Ironwood receives tiered royalties from partners including AstraZeneca in China and Astellas in Japan. The U.S. collaboration accounts for roughly 98% of revenue. Ironwood's pipeline centers on apraglutide, a once-weekly GLP-2 analog in development for short bowel syndrome with intestinal failure (SBS-IF), a rare condition in which patients depend on intravenous nutrition to survive. Apraglutide aims to improve gut absorption and reduce or eliminate that dependence. After a dosing issue in the initial Phase III trial, the FDA required a confirmatory trial (STARS-2), with site initiations planned for mid-2026. Ironwood operates with a lean cost structure of roughly 100 employees, outsourced manufacturing, and AbbVie handling most U.S. commercial infrastructure for LINZESS. Cash from LINZESS funds the apraglutide program and debt repayment, and Ironwood expects to self-fund through a potential apraglutide launch.