  Higher order clustering statistics of Ly$\alpha$ forest provide a unique
probe to study non-gaussianity in Intergalactic matter distribution up to high
redshifts and from large to small scales. The author presents a brief review of
his work studying the spatial clustering properties of Ly$\alpha$ absorbers,
with emphasis on 3-point statistics. The observational side of this involves
redshift-space clustering of low-$z$ ($z<0.48$) and high-$z$ ($1.7<z<3.5$)
Ly$\alpha$ absorbers. This is complemented with astrophysical inferences drawn
from N-body hydrodynamical simulations. We also use simulations to study
2-point and 3-point clustering statistics in the transverse direction using
projected QSO triplet sightlines. Such studies will become possible
observationally with upcoming surveys.
