-- Detects if anything is inside the player's collision hull
local player = player_youre_tracing
local pos = player:GetPos()
local mins, maxs

if (player:Crouching()) then
    mins, maxs = player:GetHullDuck()
else
    mins, maxs = player:GetHull()
end

local tr = util.TraceHull({
    start = pos,
    endpos = pos,
    mask = MASK_PLAYERSOLID,
    collisiongroup = player:GetCollisionGroup(),
    filter = player,
    mins = mins,
    maxs = maxs
})

if (tr.Hit) then
    -- Something is inside the player
    -- tr.Entity will provide exactly what
end