Talk to Ent Specialist on Blood In Mouth

My niece has suffered from appendicitis issue and got her surgery 2 months back. She was not diagnosed peoperly approximately for 2 months ,later she started have blood in her mouth collected at random times. No signs of pain anywhere. Got checked from several doctors including ENT,medical specialist and gastrointestinologist. No one identified the cause and lastly recommended her endoscopy. Endoscopy of mouth area got no identified abnormality, now suggested lower body endoscopy. I doubt their intutions. Does this problem relates with dr.khalil's area of expertise ?