Thank you for the query.
Stomach burning and back pain can be caused by gallstones or acute pancreas inflammation
. However both this condition should give also nausea and vomiting.
Peptic ulcers are also possible. But it does not give back pain.
If you doctor suspects peptic ulcer, he should perform gastroscopy. Its because stomach cancer
can give very same symptoms.
Anus itching and bright red blood in the tissue is most likely caused by hemorrhoids. It is usually caused by constipation and hard pushing on the stool.
Constipation and bloating can indicate serious large intestine disease, especially if you are over the age of 50. Please visit general surgeon
for rectal examination
and consider colonoscopy.
Hope this will help.