My son is 5 and has been having very loose/mushy stools and sometimes full out diarrhea on and off for a little over 3 weeks now. Most are light brown and very foul smelling. He varies how many BM's each day. Some days it has been 2-3 and some have been 3-5. He has no other symptoms of a cold/virus and is just as active as always. He has had very few solid BM's throughout this time period, but has had a couple and we then think he might be getting back to normal until the next BM when it is back to the diarrhea again. He is getting plenty of fluids (lots of water) and is urinating frequently. He does however seem to be drinking more than usual. 2 days after the loose stools/diarrhea started he had his normal yearly checkup with his doctor and we weren't concerned at that time because it just had started and thought it was just a "bug" going around. He had blood work drawn at that appt. for other unrelated issues. Thyroid was normal but he tested positive for iron definicency anemia. His doctor recommended he start a multi-vitamin w/iron and retest in 6 months. We started right away (about 3 days after appt). He was still at that time having the loose stools and thought that the iron (which we knew often causes constipation) would maybe help correct the loose issue. He has been on those ever since (2.5 weeks) and we are concerned that the loose stool continues. Last week he had complete watery diarrhea for two days. By the 2nd day I took him back in to the doctor and he ordered a stool sample. By the time I got the stool sample it was loose/soft/mushy not watery by that time. One week ago today, we got 2 out of 3 test results and both were normal. We have not heard back yet on the 3rd result but for the past 5 days he has been seeming to get a little better. Sometimes soft but not too loose and sometimes some solid pieces. Today he had a BM right away in the morning that was soft/mushy and very foul again, but a good amount. Within one hour later, he had a mix of very loose/mushy and watery diarrhea in a large amount, and again some more about 30-40 mins. later. However this time I noticed bright red thick stringy-like pieces in it (it looked like pieces of fruit roll-up). He has not had any new or different foods over these past 3 weeks at all. I checked with his daycare about any fruit roll-ups or snacks like that and he didn't have anything like that at all. He has not had any tomatos or red peppers or anything like either. I'm concerned that this could be blood. He tested negative for having any parasites in his stool. I'm wondering if the iron is making this issue worse. He has no known allergies. Any thoughts?