What causes a thickened ce wall?

CT shows thickening at point where small and large bowel meet. Going for diagnostic colonoscopy in 10 days, but concerned. Anyone know what this might be? Symptoms - profound fatigue, nausea, lack of appetite, alt. const/diarr, low grade fever (intermittent, cleared with antibiotics) night sweats, muscle aches, dizziness. I have divierticuli on descending colon that don't give me trouble, though the fever might have been from that.