In its earliest stages, bowel cancer usually has no symptoms, according to NIHSeniorHealth. However, as the cancer grows, it can cause a number of noticeable digestive symptoms, such as blood in the stool, constipation and diarrhea.
Any change in bowel habits could be an early sign of bowel cancer, according to NIHSeniorHealth. Particularly, individuals should watch out for changes in the frequency of their bowel movements. Both constipation and diarrhea are possible signs of bowel cancer, and another possible symptom is a feeling that the bowel does not completely empty during defecation. Gas pains, bloating, unusual feelings of fullness, cramps, tiredness and vomiting can also indicate bowel cancer, but they can also be caused by other conditions.
NIHSeniorHealth also recommends that people look at their stools in order to spot the early signs of bowel cancer. Stools that are narrower than usual can also signify this type of cancer. Blood in the stool, whether bright red or much darker in color, is also a symptom.
According to NIHSeniorHealth, bowel cancer does not often directly cause pain in the bowel during its early stages. For this reason, it is important to look out for the other symptoms and to consult a doctor if any of them are present.