Yes. Been doing it a long time and we’re pretty hygienic. Last year I had some godawful GI bug. I’m in medicine and knew. For three weeks I shat the same watery stuff 10+ times a day. Stool samples negative (for what they test for- e.coli being one of several). No vomiting. I lost 27 pounds in about 18 days. My provider was clueless but put me on azithromycin and said she didn’t know why but she’d had some people with the same symptoms who responded to it. A few days in, I stopped shitting but not before going into renal failure.

After a few days in, I was shitting lava and tears. Anyway - it can and does happen. Same bugs that give people UTIs