can cat's poop change after taking meds?

hello

Two weeks ago I took my kitty to the vet for  tooth extraction and cleaning. They also did blood test and all is looking good, thyroid was too low so my vet decided to lower her dose of methimazole. Before the tooth extraction I had to give my cat one pill of some kinda medication for 7 days to help with gum healing. While taking pills I noticed that her poop changed color to gray and smelly. Now she has been taking a generic methimazole ( two weeks now) and once again her poop is not looking how it should, it is yellowish color but pretty solid. Also I noticed some weight loss. She is eating well and acting well. Doctor said her liver is fine and other organs. My thoughts are that generic medication is doing this to her and tomorrow I am getting the stuff she was taking before. Any of you have any experience  with such issues ? Thank you

What was the medication you were given for gum inflammation? I would be very concerned with gray smelly stools, what did your vet say about this?

My kitty was hyperT and took Tapazole prior to receiving R131- I know it can cause vomiting, nausea and a variety of allergic reactions, however I think you need to call your vet to see if the change in stool is normal because I do not think that sounds normal. I would also be very concerned about the weight loss.  My vet checked my Tiger's T4 and FreeT at least every 3-4 months.

Here is a link to the Yahoo Hyperthyroid Group, I found it to be a great resource. https://groups.yahoo.com/neo/groups/feline-hyperT/info

Please keep us posted!