<s>[INST] I recently had a Inguinal hernia repair 4 weeks ago (and a lot of scar tissue removed resulting from my aorta bi-fem bypass I had done one year ago). At about the end of the 2nd week, I will wake up in the middle of the night  stretching. My abdomen will get real tight and be crunch up. My ab muscles seem to do it automatically. Also, as this is happening and I try and turn onto my side, I have excruciating pain.  Once I am up and out of bed, this all goes away.  Why is this happening? [/INST] Hi.Thanks for your query.This is a very rare but a known phenomenon.Why this happens , no one knows.This may occur due to discharge of electrical impulses due to new formation of nerves supplying the muscles in this particular area.There is no specific treatment. Take a help of a neurologist- Medicines like tegritol etc may help. These need prescriptions-- </s>