Passing hard pellet-like stool may cause anal fissures, small anal lining tears that will lead to blood spots on the stool surface.
Being constipated can result in developing internal and external hemorrhoids.
Internal hemorrhoids aren't painful and the only sign of their presence is blood on the stool, toilet paper or in the toilet bowl.
Mucus produced by lining cells of colon, eases the process of stool passing, and since the mucous serves to protect your digestive system, it is not unusual to find increased amounts of mucous when suffering from constipation or diarrhea.
Increased amounts of mucus appear with anal fissures, and in cases of irritable bowel syndrome (constipation or diarrhea predominant forms).
Constipation is a common side effect of certain anti-anxiety drugs.
Also, it is possible that you are experiencing symptoms of irritable bowel syndrome, a functional bowel disorder, in many cases triggered for the first time by excessive stress in life.
In other words, initial episode of IBS can follow a major stressful period in life.

Best wishes!
Marija