Hello,
For a young and otherwise healthy individual the most likely cause is hemorrhoids, particularly if
constipation is an issue for her. Hemorrhoids characteristically bleed after passing hard stool and the blood is not homogeneously mixed with the stool but it's rather like if it's been spilled over them. Sometimes the blood is apparent on the toilet paper only. Your
primary care doctor or a gastroenterologist will help you with the required investigation.
Regarding the other issues, MRSA can be difficult to eradicate and you'd better talk with an infectious diseases specialist. Antibiotics by mouth are not usually enough and repeated use may result in the development of resistant pathogens.
Weight loss also requires investigation for various causes including
thyroid disorders and her
depression and anxiety (but not limited to them only).
So in conclusion, she'd better talk with her primary care physician for the issues you have mentioned. The MRSA may require expert help, since the antibiotics by mouth will be ineffective in many cases.
Hope I have answered your query. Let me know if I can assist you further.
Regards,
Dr. Panagiotis Zografakis