Causes of Obstructed Bowel :
The bowel can be obstructed due to a bowel wall lesion, an obstruction in the lumen or an extrinsic abnormality. The commonest cause is a bowel tumour.
Bowel tumour - often in the sigmoid colon
Inflammation of the bowel wall in diseases such as diverticulitis, ulcerative colitis, crohns disease
Extrinsic compression from a pelvis mass
Causes of Ileus :