Hematochezia
Bright red or maroon-colored bleeding that comes from the rectum
Usually represents<unk> 
May represent upper GI source if bleeding is brisk
Usually accompanied by hematemesis and hemodynamic instability
Melena
Usually represents bleeding from upper GI source (see upper GI bleed)
May represent slow bleeding from<unk>  GI source
Bright red or maroon-colored bleeding that comes from the rectum
Usually represents<unk> 
May represent upper GI source if bleeding is brisk
Usually accompanied by hematemesis and hemodynamic instability
Usually accompanied by hematemesis and hemodynamic instability
Usually represents bleeding from upper GI source (see upper GI bleed)
May represent slow bleeding from<unk>  GI source
Lower gastrointestinal bleeding
Upper GI Bleeding
Gastrointestinal bleeding 
Diverticular disease
Colitis
Diverticulosis
Leaking G-tube
Diverticulitis