This is Dr. Christie! I am a licensed veterinarian and would like to try to assist you!
I am sorry to hear Gem is not feeling well!
I have a few quick questions to gather a bit more information so I can better help you and Gem!
Is Gem attempting to urinate or have a bowel movement when she is unable to go?
Could she have eaten anything she shouldn't have such as a dog toy or sock or rock,,etc?
Is Gem spayed? If not, when was her last cycle?
Is she currently on any medications or have any previous medical issues such as urinary stones, etc?
Thank you in advance for your answers!
Thank you for the information!
While I cannot provide an exact diagnosis, these are my concerns and advise with the history and information you have provided!
My primary concern is that Gem may have a uterine infection. Since she cycled a month ago and is an older intact female, I am concerned that she may have developed a pyometra or infection in her uterus. Essentially her uterus begins to fill with pus. This inflammation and infection can cause vomiting, anorexia, and can sometimes upset the gut and cause irritation to the colon (the uterus sits below the colon and can put pressure on the colon). This is a situation in which she should be checked out by your vet very quickly as it can be life threatening.
Two other differentials I would consider are colitis and a possible urinary tract infection (UTI) or bladder stone.
Colitis is the inflammation of the lower GI tract, or the colon. This can result from dietary indiscretion (possibly eating something she is not used to, etc), allergies, parasites, polyps, neoplasia. Many times you will see straining to defecate and producing small amounts to nothing at all. Most times we see a diarrhea associated with this. Rarely do we see vomiting, but it is possible.
A bladder stone or UTI can cause irritation to the urethra (outflow to the bladder) and cause pain/inflammation in the colon (the urethra sits below the colon). We see quite a few patients, both feline and canine, that will present with what seems to be constipation, but is truly secondary symptom to the primary cause.
Here is an article concerning pyometra: http://www.petplace.com/dogs/pyometra-in-dogs/page1.aspx
I would definitely recommend getting Gem into your vet today if you can to have her checked out. A hands on physical can rule in and rule out alot of things!! Your vet may also recommend checking some bloodwork to look for an underlying cause!
Please let me know if you have any further questions! I will be offline for a few hours, but will be back on later this evening should you have any concerns or further questions!
Best wishes for a speedy recovery for Gem!!