pugs vomiting and loose stools

Question
I have two pugs and have two questions, hope you don't mind.  My 5 year old rescue pug named Toby has, up until now, been very healthy (thank goodness).  He eats grass whenever he gets the chance and has since I resuced him at 6 months old, so I figure it must settle his tummy.  The last 3 days, he has refused to eat (he always has a good appetite).  Last night I brought him outside for his evening walk and he started eating some weeds which I pulled him away from.  he vomited almost all night long clear thick liquid. Saliva was drooling from his mouth all night and he would not lie down, he would just sit next to me and close his eyes.  Right now he is lying beside me snoring away (I gave him a Tums crushed in water which seemed to settle his stomach) but I'm concerned about him not eating and the thick saliva, he also has very strong gas odor.  What could be causing this?  I changed his diet about 5 months ago with no ill affects.  

Also, his brother, Buddy a 7 year old pug has been experiencing very loose light brown stools, sometimes a little clear and slimey.  His anus area smells really bad and when I washed him with baby shampoo, I noticed a tiny amount of blood on the face cloth.  He hasn't been himself in a few weeks, tail is always down, not curled as usual.  Although I can get him to get excited and play like he always does.  I have recently moved and haven't found a vet yet which is why I'm asking you if you could help.  
By the way, I just want to say that I read all of your recently asked questions, and I have picked up alot of information from it.  Thank you for making yourself available to us/me.  Sorry for such a long question.

Answer
Eva-

Thanks for the questions, and don't worry about asking two at the same time!

I would be a little concerned about a bug at this point with Buddy- perhaps coccidia. A strong odor is usually from decomposing blood in the feces, and you are seeing some blood around the anus. Lethargy, refusal to eat.. all classic signs of an intestinal parasite or bug. Light, peanut butter colored loose stools are also classic of coccidia.

Toby could have a similar bug as well, especially with a strong gassy odor. The vomiting and drooling (indicating nausea) could be because he ate some weeds that did not agree with him, and may not be connected. However, because of Buddy's problems, I would be concerned. If both are sick, there usually is a common problem.

I think its time for a fecal at the vets. Try talking to neighbors or trainers in the area and looking for a vet reference. Either way, if its an intestinal parasite or bacteria, you really want them to get in ASAP.

I hope they feel better!!