Not all tumors are malignant. Many are benign, but they can cause serious trouble within the bowel by obstructing the lumen or tube. Fairly large non-malignant tumors may develop within the stomach, causing a chronic loss of blood.

Although not malignant, these can be serious. Colon polyp are also common and are often responsible for blood in the stools. Over half of those who have polyps in the colon eventually develop cancer as well.

For this reason, all polyps should be removed, either through the sigmoid scope, if they are low enough down, or by respecting in the involved portion of the colon. Before doing so, the patient should have a thorough medical examination, and also x-ray of the large and small bowel. This is particularly important an all cases of rectal bleeding or unexplained loss of blood from then stomach or bowel.

image courtesy: gjgastro.com