Abdominal pain
Abdominal distension
Distention is greater if the ileocecal valve is competent (it creates a closed loop obstruction). If the ileocecal valve is not competent, you are more likely to see some dilation of the small<unk>  as well 
Obstipation
Vomiting
Palpable abdominal mass (could be distended<unk>  or could be tumor causing obstruction)
Fever and tachycardia should prompt investigation for gangrene and perforation
Distention is greater if the ileocecal valve is competent (it creates a closed loop obstruction). If the ileocecal valve is not competent, you are more likely to see some dilation of the small<unk>  as well
Large bowel obstruction
Abdominal aortic aneurysm
Small bowel obstruction
Aortocaval fistula
Malignant bowel obstruction
Acute gastroenteritis
Epiploic appendagitis
Aortoenteric fisulta