What Causes Lumps In Stool After Treatment For Constipation?

I have been dealing with some severe constipation over the last few weeks due to opioid pain medicine that I have been on. I haven t had a normal bowel movement for two weeks. I just used a otc laxative suppository and produced a large bowel movement that was mostly formed with some loose/watery stool. My question is I noticed that some of the stool was formed in round balls (golf ball size) with a white coating. I put on exam gloves to examine what it was (I am a paramedic so I am no grossed out by this and was curious as I have never seen this before). The stool was rather firm/hard on outside but had texture of drywall mud or melted fudge when squeezed. The white coating cracked when pressure was applied and reminded me of a glaze on a glazed donut that has sat out. Sorry for the food references but that s exactly what it was like. what would cause this white glaze?