Common symptoms of bowel cancer include blood in the stool, a prolonged change of bowel habits, a lump in the anus or abdomen, weight loss and anemia. Patients may feel bloated, tired, breathless, feel sick and have abdominal pain or cramps, explains Cancer Research UK.
Most patients do not show any symptoms during the early stages of bowel cancer. As the disease advances, some patients experience prolonged tiredness, paleness and general body weakness, according to Better Health Channel. Bowel cancer may cause bowel obstruction, and patients may experience severe abdominal pain, swelling of the tummy, vomiting and be unable to pass stool. Bowel obstruction requires urgent medical attention, notes NHS Choices.