I have IBS for 50 years and have considerable malaise. I decided to investigate - could this 'mucus' be a 'slime mould'. Answer? Well - depends how loose your terminology is. I have unambiguous evidence of a Labyrinthuloides sp - sometimes called 'net slimes' but finding the anastomosing nets is not easy and when you do it really does not anastomose very much. Looks like the cell signalling mechanism tries to avoid the trophic cells annoying each other. Basically there are 5um thick hyaline plates of ectoplasm separated by vesicles and extending beyond the edge of some of these plates you can see the anastomosing tracks and the trophic cells many of which are rather small at 3um but these cells are undergoing mitiotic division with diagonal cleavage characteristic of the group. This does not account for your mucus strings but if you have flat mucus or a large mucus slug - possibly. You will not easily see any structure but expect white cells of variable size, hyaline ectoplasm, brown streaks and bacteria and yeasts in the ectoplasm. No streaming of the cytoplasm. No obvious structure. Looks like a rocky foreshore. You could try submerging it for a a while in the U bend of your WHB and then see if it climbs out again. Marine organism evolved via inter tidal estuarine and flood plain environments. Go figure. On dung only very careful phase contrast microscopy will reveal the disassociated vesicles - they occur in clusters and start at 2um. And no - they are not gas bubbles. Sometimes bacteria inside and evident Brownian motion and when you squash them you get a ring of liquid.
Next - rope like mucus. I am getting parallel strands of mucus which anastomose fairly rapidly. Look twisted and rope like when first passed but with a little TLC they straighten out just fine. Hyaline ectoplasm, brown filaments and if you get a complete organism you may, with a dissecting microscope, see cytoplasmic streaming. Possibly two species - in one there are siphonaceous pseudo rhizoids with spirally banded tube in hyaline ectoplasm. Both types have simple vase like tests so these stack up as possible Foraminifera sp. The only reference I have found to their presence in the human lumen is in the Textbook of Zoology, Parker & Haswell p51 which states that Chlamydophrys stercorea is considered harmless but needs to pass through the gut of Man or a higher animal to develop into an ameboid phase. I may be seeing that but need more investigations.
If you are a troll, please go hide under a bridge. If you have a lab and can support my studies - culture media for Labyrinthuloides sp. would be cute - then let me know. And in case you are wondering I can evidence everything which I have written here.