According to Steve Corkran of the Bay Area News Group, Hayden underwent a surgical procedure to clear out abdominal scar tissue.
Perhaps the most important bit of news came from the Los Angeles Times' Sam Farmer, who mentioned that the operation was unrelated to the previous heart injury and subsequent surgery that almost took Hayden's life.
Though precise medical details are unavailable to the public, speculation suggests Hayden's most recent concern stems from an unavoidable complication of abdominal surgery: adhesions.
What are adhesions? First, let's review Hayden's injury and medical path so far.
As NFL.com's Andrea Kremer wrote in April, concern over internal bleeding forced doctors to cut into Hayden's abdomen to look for the source, as when bleeding is extensive enough, direct visualization is sometimes the only way to determine from where the bleeding is coming.
Surgeons eventually found the source—in his chest, not his abdomen.
The tackle tore Hayden's inferior vena cava (IVC)—the largest vein in the body responsible for bringing blood from the lower body back to the heart. Surgeons repaired the tear, and the rest is history.
Regardless, that need to look inside Hayden's abdomen probably led to Tuesday's news.
When surgeons cut into Hayden's abdominal cavity, they passed through several layers of connective tissue, muscles and the tissue layer making up the abdominal cavity itself—called the peritoneum. Within the peritoneum are the intestines, spleen, liver and other organs.
The intestines are quite mobile and constantly in motion within the abdomen. Under normal circumstances, they and other organs smoothly glid...
Article Source: Bleacher Report - Oakland Raiders