My boyfriend for the past week and a half is having bad cramping, pellet like, mucousy stools with intermittent fever. any idea what the problem is?

See physician: Sounds like your boyfriend would best be served by seeing his physician. Can't diagnose without talking with and examining him -- probably also getting some lab studies.

Bowel inflammation: This could be infectious or non-infectious inflammatory bowel disease. He should be seen by a doctor, perhaps a GI specialist and diagnosed and treated appropriately.