The least common type of intussuception is -: (A) Multiple, (B) Colocolic, (C) Ileoileal, (D) Ileoilecolic
Answer is A. Types of intussusceptions in decreasing order

Ileocolic (~77%)
Ileo-ileo-colic (~12)
Ileoileal (~5%)
Colocolic (~2%)
Multiple (1%)
Retrograde