Rashad Butler – What happened?

With all this talk over drafting a LT, I was wondering why no one was talking about Rashad Butler.

Butler was a solid player when drafted in the third round of the 2006 draft. He was a bit on the smaller side, but the scouting staff felt they could bulk him up and he would be the eventual starter. However, he actually lost weight and while he stayed extremely athletic and physically gifted, he did not have the size to fend off NFL caliber defensive ends.

The Panthers then cut him after the 2007 training camp.

The Houston Texans picked Butler up. Soon after the signing, Butler was diagnosed with ulcerative colitis, a rare disease that causes open sores in the colon. Soon after treatment, Butler was able to easily gain weight and currently is listed near 300 pounds.

Question: How was this medical condition missed by the Panthers training staff, resulting in the loss of a third round pick that is the most needed position today?