There are many medical reasons that can cause black stools that are tarry with a foul smell, but sometimes dark stools are caused by eating certain foods or taking iron supplements. However, black stools can also be a result of bleeding, and the darker color indicates that the blood could be coming from a point in the upper gastrointestinal tract.
Gertrude Levandowski survived a 96-hour procedure at a Chicago hospital to remove a giant ovarian cyst; the longest surgery. The second longest surgery ever was 40 hours long and that was to remove 6 limbs from a 8 limed baby in India. But the most common longest surgery is spinal cord surgery it is a 14 hour surgery.
Casualty longest medical drama in the world and is still going on today. A woefully inaccurate list that fails to mention its based on only US shows. The UK has some of the longest running TV shows in the world including The Sky At Night (55 years), Coronation Street (52 years.