Guess the disease

History of three month loose motion , weight loose from 72 to 66kg , pins and needles feeling and numbness of palms and fingers (only in hands), hyperpigmentation ,#ulcers in mouth cured after giving 15 days supplements of vit b12 ,loose of sense of taste since 5 months, burning sensation in anal region, suffering from migraine from last 10 years Age of patient is 58