However, passing mucus in the stool, especially if it is a new symptom, should still be mentioned to a physician at the next office visit. Mucus without an underlying cause, such as one of the pre-existing conditions mentioned above, is a change in bowel habits and should be reported to a physician immediately.
By Mayo Clinic Staff. Coughing up blood can be caused by a variety of lung conditions. Coughing up blood can take different forms: The blood may be bright red or pink and frothy, or it may be mixed with mucus. Also known as hemoptysis (he-MOP-tih-sis), coughing up blood, even in small amounts, can be alarming. However, producing a little blood-tinged sputum isn't uncommon and usually isn't serious.
If you notice an increase in stool mucus that occurs regularly, or is accompanied by bleeding or a change in bowel habits, contact your doctor, the Mayo Clinic advises. That's because larger amounts of mucus associated with diarrhea may be caused by intestinal infections that require medical attention. Also seek medical attention for bloody mucus in your stool, or mucus accompanied by abdominal pain.