Type 4 Waardenburg syndrome (also called Waardenburg-Shah syndrome) is characterized by symptoms of Hirschsprung's disease in addition to the classic features of hearing loss and pigmentation abnormalities.
[Effects of a vitamin B complex on functional recovery after nerve injury (author's transl)]. Hasegawa K, Mikuni N, Sakai Y. Functional recovery after nerve crushing was investigated in the following manner: Under pentobarbital anesthesia the sciatic nerve of the rat was crushed at the level of the hip (proximal crush) or the thigh (distal crush).
Stimulating the vagus nerve increases the release of histamine by stomach cells, which helps release stomach acid (R). So, low stomach acidity is usually, in part, a vagus nerve problem. By releasing intrinsic factor, the vagus nerve is important to help you absorb vitamin B12 (R).