Dear concerned friend, Some people are allergic to crystal meth due to which the clotting abilities of blood are affected and the patient ends up bleeding from stomach and in urine. It is advisable to visit an ER for blood investigations and if needed prescribe appropriate drugs. As this condition can be life threatening, pls take your friend to ER and keep him/her away from meth consumption. Also look for other signs of allergy like watering eyes and nose, red rashes all over the body, swelling along the injected vein with redness and pain and red flushing of face and eyes.