Just to correct a typo in the first answer: the total number of nodes for a tree of depth L is (N^(L+1)-1) / (N-1)... (that is, to the power L+1 rather than just L). This can be shown as follows. First, take our theorem: 1 + N^1 + N^2 + ... + N^L = (N^(L+1)-1)/(N-1) Multiply both sides by (N-1): (N-1)(1 + N^1 + N^2 + ... + N^L) = N^(L+1)-1.
Malignancy is the most common cause of large bowel obstruction in older patients. Colon carcinoma without obstruction does not usually cause acute abdominal pain. Diverticulitis and colonic volvulus (i.e., narrowed, twisted lumen with a birdâs beak appearance) are less common causes of large bowel obstruction.4,5,14,35.
Other causes include hernias and Crohn's disease, which can twist or narrow the intestine, and tumors, which can block the intestine. A blockage also can happen if one part of the intestine folds like a telescope into another part, which is called intussusception. In the large intestine, cancer is most often the cause. Other causes are severe constipation from a hard mass of stool, and narrowing of the intestine caused by diverticulitis or inflammatory bowel disease.