cat having diarrhea and blood in poop

My 8 year old cat has been having diarrhea for a couple of weeks. I also found blood in his poop. Please see it in the pictures. We has taken him to a local vet and did a fecal test and blood test. It didn't show anything positive(report attached). The doctor also prescribed 'metronidazole', but it didn't help that much. Does any doctor know what's going on? Thank you so much. From an anxious cat mom :(

Hello - and thank you for telling us about this interesting case.  It can be very demoralising to interpret the time, money and effort put into this case as 'havent found anything positive.'  I obviously have no way of knowing the details or quality of these tests, but your vet may well HAVE found something both useful and positive; ie that Giardia, unusual bacteria, roundworms, whipworms etc are unlikely to be causing the haemorrhagic poo.  This is good news although, in light of it, I dont understand their rationale for giving Metronidazole.  Nor have I seen a vets report or blood test, so have insufficient information to usefully give a second opinion - indeed, we do not do that on this site. A good way to progress the situation would be to ask your vet, perhaps with the input of their lab pathologist (those people study the research and will have looked at data from a large % of cases in the UK) to list the most common reasons for haemorrhagic diarrhoea in cats of this age.  It is unlikely to be bacterial.  Is hyperthyroidism, stress or pancreatitis a possibility for your cat? - blood tests might already have started to rule some possibilities out.   Im not clear from the photo whether there might also be an increase in hair in your cats' stool, which might hint at overgrooming eg due to pain or stress - but then again, your cat may be a hunter.  Again, things that your vet may consider in their differentials (possibilities) list. The best things to establish from your vet are - what causes have we ruled out?  What could it still be?  Which courses of action have the best stats supporting them at this stage (your vet shuld outsource this question eg to the lab already dealing with the case, if they do not know). I hope that something there is useful.

Ps on one of the photos, it looks as though there is something solid protruding from the top end of the pooh (the bit that, with some imagination, looks like a wrong way round capital 'G' - protruding from the top end, given the way round that the photo is now on the screen).  I wondered whether you noticed whether that was the same consistency as the rest of the sample?

It is worth noting that the location of the faeces suggests a hurried toileting event - again, this is a very vague sign that can suggest a wide range of things, but worth menioning to your vet as it can have implications regarding feline social stress and also various diseases.  Furthermore, I am assuming that the lines in the faeces are 'hairs' but if that is not obviously the case,  always ask your vet to check again.  I hope that you and your vet can work together to put this case into full context and understand what my be going on.  Because Ive mentioned pooh, although obvious, Im obliged to tell you that cat faeces should be handled only using gloves and never by pregnant or hoping to be pregnant women.

It sounds like your kitty might be having a bit of a tough time. Seeing blood in your cat's poop is definitely not something to ignore. While I'm no vet, from what I've heard and read, this could be due to a few things like infections, parasites, or even dietary issues.