Can you add a picture of the snake through the gallery? It might have a neuro morph like spider. What is the ambient temperature in the room? Is the heat bulb on a thermostat? It could also be from overheating or improper temperatures. For the diarrhea a herp specialized vet appointment is a must. Do you have any other reptiles? If so she should be quarantined away from them (if she isn't already). What things have you tried feeding? A 4-month fast isn't too concerning but it could be a sign of underlying problems.