Colorectal cancers may not present any symptoms at first, however, when they do, following are seen;
Changes in bowel movement like diarrhea, constipation or thinning in the stool and these being persistent for more than a few days
Feeling the need of defecation, however, continued sense of defecation afterwards
Bleeding from the anus
Bloody stool
Abdominal pain or cramps
Weakness, fatigue
Unintended weight loss
Colorectal cancers frequently cause bleeding into the digestive system. Blood may appear as mixed with stool or by making the stool appear darker; although stool might look normal as well. However, this invisible chronic blood loss may cause anemia in time. Sometimes first finding of colorectal cancer might be anemia diagnosis.