This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Intestinal Obstruction, Subject name: Surgery
Most common type of intussusceptions - 
Select and explain. 
A. Multiple, B. Colocoiic, C. lleoileal, D. Ileocolic
D: Ileocolic
Answer: D: Ileocolic 
Explanation: Ans. is 'D' i.e., Ileocolic Types of intussusception in decreasing ordero Ileocolic (~77%)o Ueo-ileo-colic(~12)o Ileoileal (~5%)o Colocolic (~2%)o Multiple (1%)o RetrogradeIntussusceptiono Intussusception is the telescoping of one portion of the intestine into the other,o It is the most common cause of intestinal obstruction in early childhood (3 months to 6 years)o An intussusception is composed of three parts :The entering or inner tube - intussusceptumThe returning or middle tubeThe sheath or outer tube - intussuscipiens.Load pointo Clinical featuresIntussusception classically produces severe cramping abdominal pain in an otherwise healthy child. The child often draws his or her legs up during the pain episodes and is usually quite during the intervening periods,Vomiting is almost universal.Initially the passage of stools may be normal while later on blood mixed with mucus is evacuated -- red currant jelly stoolAn abdominal mass may be palpated - a sausage shaped mass, which may increase in size and firmness during the paroxysms of pain.There may be an associated feeling of emptiness in the right iliac fossa (sign of Dance)On rectal examination, blood-stained mucus may be found on the finger. Occasionally in extensive ileocolic or colocolic intussusception, the apex may be palpable or even protrude from the anus,o Diagnosis can be made on :Barium enema which shows characteristic- Claw sign- Coiled spring signOn ultrasound which shows- Target sign- Pseudokidney sign.o When the clinical index of suspicion is high, hydrostatic reduction by contrast agent or air enema is the diagnostic and the therapeutic procedure of choice. Hydrostatic reduction is contraindicated in peritonitis or hemodynamic instability.