I have diabetes. Will cholestyromine powder increase my sugar?

My guess would be NO
It is used along with changes in diet. It is used to relieve itching caused by partial biliary obstruction. It may also be used for other conditions as determined by your doctor.
Cholestyramine Powder is a bile acid sequestrant/anion-exchange resin. It works by increasing the removal of bile acids from the body. As the body loses bile acids, it replaces them by converting cholesterol from the blood to bile acids. This causes the blood level of cholesterol to decrease.
There were no warning about Diabetes at all.