Hello. My dog has been very constipated and is becoming very irritable. Her anal smells like fish. We took her to the vet and they said she had to much gas in her stomach. They gave her reglan for motility. It helps a little but makes her tremble and anxious. It also seemed to make her even more constipated. We give her small amounts of benadrly for pain because she is so sensitive to pain meds. Could that be causing gas?