Does constipation occur as an isolated symptom of ms? does it always occur at the same time as other neurological symptoms?

No: The most common cause of constipation is the diet. The first thing to do is to get a history of what the patient is eating. The function of the colon is to re absorb water from the gut back into the body. Some foods act counter to that-mainly all of the grains (rice,oatmeal,barley,etc), pastas, milk, foods with a lot of pectin in them. First, reduce these in the diet before any medicinal remedies.