Derek Hough experienced unbearable pain in his abdomen yesterday that required emergency surgery and his fans have been there for him. He explained the pain as “severe” and “sharp." They happened in the middle of the night around 3 AM. That's when he went to the hospital and found out he had appendicitis. "Appendicitis is an inflammation of the appendix, a finger-shaped pouch that projects from your colon on the lower right side of your abdomen," as stated by Mayo Clinic.