L4-l5 large disk extrusion in the left subarticular and foraminal location. can this cause cauda equina?

Short answer is YES: Disk herniation is a definite for symptoms known as cauda equina syndrome. Depending upon the location in the dorsal spine symptoms may present differently. The location of what you describe most likely will cause pain or numbness and tingling sensations in the vicinity of the sciatic nerve. Would recommend a thorough neurological examination with imaging and electrical studies for more complete.

Cauda Equina: Inability to urinate or bowel/bladder incontinence is an emergency and is called cauda equina syndrome. Unfortunately this requires surgery to correct. Often times the nerves are just bruised abit and the signals aren't being sent quick enough, you may need an epidural steroid injection to relieve this irritation. Either way, i would see a pain/spine specialist to evaluate your options

Cauda equina: Very unlikely. To cause cauda equina syndrome the disc material has to be more central and occupy more than half of the canal at the L4/5 level. Cauda equina syndrome is associated with severe pain, numbness in the legs and an inability to urinate. When cauda equina syndrome occurs people go to the emergency room and don't ask questions. They simply want relief and surgery is the cure.