Hi Dear, Welcome to HCM. Understanding your concern. Thanks for your query . As per your query you have bleeding from the mouth along with constipation. The symptoms you mention in query are pointing towards allergic reaction. The allergic reaction occur due to some food or medication . But the symptoms can also occur due to certain reason like acid reflux , localized infection in mouth or trauma. I would suggest you to :- - Do warm saline gargles . - Take over the counter anti allergic drug like benadryl or zyrtec. - Avoid taking food like nuts or sea foods , also avoid spicy and heavy food. I would suggest you to consult gastroenterologist for proper examination and treatment . Doctor may order endoscopy , ambulatory acid test and x-ray of upper digestive track . Doctor may prescribe H2 blockers and proton pump inhibitor . For now avoid spicy and heavy food specially at night , eat one hour before going to bed , ear small and frequent meal and take light walk after every meal . Also consult dentist for examination .Doctor may order x-ray to find out if there is abscess due to infection in tooth .Dentist may prescribe antibiotics , perform root canal after antibiotics course or may extract tooth. Hope your concern has been resolved. Best Wishes, Dr. Harry Maheshwari