Melena with no apparent cause

My girlfriend is 18 years old. Three days ago she had two bloody stools (actually, there was no fecal matter, only dark blood). She went to the Emergency Room and they admitted her in. During the next day she had another two or three of the same dark blooded stools. She was scheduled for an endoscopy two days after she was admitted, time in which she was give controloc i.v. two times a day. The doctor who performed the endoscopy said that he could not see any sign of gastritis or ulcer and that her upper digestive system is perfectly normal. He doesn't know what the cause of the melena was. He  said that the source of the bleeding might have been stopped by the controloc she was given. Can there be another cause for her melena?

[cprnalex]

I would also like to add that she has been under a lot of stress lately with school and some exams. Also, she isn't taking any medication, she's not taking any birth control pills. She also has a minor anemia

[PA_S]

Black tarry stools (melena) are generally a textbook definition of an upper GI bleed. The most common cause is a peptic ulcer. So what's going on in your GF's case?

1. And endoscopy usually only covers the esophagus, stomach and upper part of the duodenum (the first part of the small intestine connected to the stomach). If the bleed was caused by something in the jejunum or ilium (other areas of the small intestine), they would be hard to pick up as these areas cannot be visualized during an endoscopic procedure.

2. Bleeding in the ascending colon, such as an ulcer, has also been known to cause melena. A colonoscopy could be needed to diagnose this.

3. Certain foods and drugs can cause melena.

Now, you mentioned she has minor anemia; do you know what kind of  anemia? ฺำIt would be interesting if you said "iron deficiency anemia," because whenever a patient presents with iron deficiency anemia, you must think "GI bleed" and try to rule that out as a cause of anemia.

[patient915]

Welcome to the gastroenterology community!  This is definitely not normal and it needs to be checked out by a doctor.  I agree with PA_S that she needed not just an endoscopy but a colonoscopy (lower endoscopy).  I would recommend talking to a doctor about getting a colonoscopy to see what is wrong.  She might also need a CT scan but that could come after the colonoscopy.

[cprnalex]

I don't know exactly what kind of anemia she's got. After a couple of days of normal stools, she again experienced melena. She'll be getting a colonoscopy the day after tomorrow. Hope it all works out all right!
Thank you for all of your help!! I'll keep you posted with the outcome in case someone is in a similar situation and is looking for a heads-up.