Can probiotics cause blood in your stool or even tomatoes not to digest properly. I ve been taking a regime of supplements including a probiotic for 9-12 months and in the last couple weeks have noticed some blood in my stool and when eating a lot of tomatoes what looks like some of the tomatoes not completely digested. Also in last few days also seeing some pink colored blood on tissue after I wipe after bowel movement. I am an investigator and I spend a lot of time sitting in my car on surveillance.