yes an internal hemorrhoid can cause bleeding as well as a significant amount of pain. If you seem to be losing a significant amount of blood I urge you to seek medical attention of some kind. a GI bleed even from a hemorrhoid can be dangerous to your health if not treated.
Internal hemorrhoids can be very painful & can bleed a lot leading to anemia. At the very least see a proctologist & have a sigmoidoscopy, they can do it in the office & it's not painful. Bleeding from the rectum can also be an early warning sign of cancer. If its fresh red blood it's coming from nearby, dark tarry stools are a sign of gastric bleeding. You may have IBS which causes the abdominal pain & increases the occurance of defacating. This can irritate the hemorrhoidal tissue causing swelling & bleeding. Definitely see a GI specialist. Good luck!
No, I think you should get a colonoscopy done. See a GI doctor right away.
Hemorrhoids do bleed but not a lot. You could have a fissure, bleeding ulcer, polyps or other serious problems. Since you have buring in your stomach it might be a bleeding ulcer so a gastroscopy and/or upper GI may identify the problem.
take care