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.
The sigmoid colon is the most common site of volvulus and accounts for 5% of large bowel obstruction. It is usually seen in the elderly or those with psychiatric illness. It is the most common cause of intestinal obstruction in Africa and Asia, where the incidence is 10 times higher than in Europe or North America. Paralytic ileus describes the condition in which the bowel ceases to function and there is no peristalsis. Intestinal pseudo-obstruction is also called Ogilvie's syndrome.