Acute mechanical large bowel obstruction should be operated early because of the risk of -
• Virtually all patients with complete acute large bowel obstruction require prompt surgical intervention and should not undergo a trial of non-operative management
• Acute large bowel obstruction in patients with competent ileocecal valve is a true surgical emergency because of high chances of perforation (MC site: Cecum) 
• Once diagnosis has been made, surgical exploration should be undertaken as soon as possible after appropriate resuscitation
Respiratory embarrassment due to abdominal distension
Electrolyte imbalance from vomiting
Septicaemia from bowel contents
Closed-loop obstruction and caecal perforation