What causes Guillain-Barré syndrome? It's not clear exactly why this happens, but the condition often happens after an infection; especially an infection of the airways, such as flu, or an infection of the digestive system, such as food poisoning or a stomach bug (gastroenteritis). What is Transverse Myelitis? Transverse myelitis is an inflammation of part of the spinal cord. The exact cause is often not known, but it sometimes happens after infections or in people with autoimmune diseases. Common symptoms are back or neck pain, weakness or sensation changes in the arms or legs, or loss of bladder or bowel control. Myelitis refers to inflammation of the spinal cord. It can damage the insulating material, called myelin, that covers nerve cell fibers. Transverse refers to the pattern of changes in sensation—there is often a band-like sensation across the trunk of the body, with sensory changes below that area.