| Etiology | Pathophysiology |
| Constipation | Impacted feces, obstipation |
| Adhesions | Malignant |
| Postoperative | |
| Postradiation | |
| Tumor mass | Single or multiple |
| Invasion and blockage of bowel (apple core) | |
| Extrinsic compression | |
| Strangulation | Around tumor |
| Around adhesions | |
| Ileus | Drugs |
| Peritonitis, hemoperitoneum | |
| Ascites | Large amount of abdominal fluid |
| Nonmalignant mass | Abscess, phlegmon |
