| Sign or symptom | Ileus | SBO |
| Abdominal distention | May be present | May be present |
| Bowel sounds | Usually quiet or absent | May be high pitched, may be absent |
| Obstipation | May be present | May be present |
| Pain | Mild and diffuse | Moderate to severe, colicky |
| Peritoneal signs | Absent | May be present |
| Radiography | Dilated loops of bowel, paucity of colonic gas | Dilated loops of bowel, differential air-fluid levels, paucity or absence of colonic gas |
| Fever, tachycardia | Absent | Should raise suspicion |
| Vomiting | May be present | May be present, may be bilious or feculent |
