My Boyfriend Had A Temporary Colostomy Last Month Due To

My boyfriend had a temporary colostomy last month due to a failed endoscopic stent. The stent was placed 8 months ago to allow stool to pass through a tumor. He was not healthy enough for stent/tumor removal, but is now passing what appears to be tumor chunks. Should we contact the surgeon? His cancer is metastatic, but can it spread more if tumor is being mulched by stent?