I have a duplication cyst in my intestines, i now have low ferritian and high crp ( cardio), could the cyst be the cause? can these cyst cause cancer?

No: Duplication cysts are fairly common and don't usually cause problems. They don't cause low ferritin. The CRP that I'm familiar with is C-reactive protein, which is a non-specific marker of inflammation. It is elevated during any kind of inflammation, including infection, injury or after surgery.

Very rarely: Low ferritin suggests low stores of iron (diet, heavy periods, GI bleeding) and CRP is very nonspecific marker of inflammation with causes too numerable to mention. It can be checked serially to monitor known and potential unknown underlying causes of inflammation. Dup cysts usually do not cause problems, unless compressing something or bleed. Only few historic cases of progression to cancer.

Cysts can transform: Duplication cysts are benign rare anomalies that arise during embryonic development. They rarely cause problems. Low malignant potential but some case reports have described malignant transformation. Not sure if the low ferritin or elevated CRP have anything to do with the cysts. I would schedule an appt with your GI doctor. They can review your records.