Reynolds pentad is a collection of signs and symptoms suggesting the diagnosis obstructive ascending cholangitis, a serious infection of the biliary system. It is a combination of Charcot's triad (jaundice, fever, abdominal pain (usually RUQ)) with shock and an altered mental status. Or sometimes the two additional signs are listed simply as low blood pressure and confusion.
It was named after the surgeon, B.M. Reynolds, who described it in 1959 along with Dr. Everett L. Dargan.