Complex sentence: In November 1997, Slocum developed ulcerative colitis which caused his weight to drop from 150 pounds to 122 pounds, and left him unable to play for a year and a half.
Split into simpler sentences: In November 1997, Slocum developed ulcerative colitis which caused his weight to drop from 150 pounds to 122 pounds. He wasn't able to play for a year and a half.