A watery diarrhea with weight loss results if the infiltration is in the lower small intestine. Of course, the entire tract from top to bottom may be involved. Many people confuse Inflammatory Bowel Disease with Irritable Bowel Syndrome, a stress-related diarrhea problem. A little vomiting or diarrhea here and there seems to be pretty standard for pet dogs and cats. After all, cats groom themselves and get hairballs.
Dogs eat all sorts of ridiculous things they aren t supposed to.
Still, many owners notice that their pets seem to have vomiting or diarrhea a bit more often than it seems they should. It might be subtle where one notices that one is cleaning up a hairball or vomit pile rather more frequently than with previous pets or it could be the realization that one hasn t seen the pet have a normal stool in weeks or months. Typically, the animal doesn t seem obviously sick. Maybe there has been weight loss over time but nothing acute. There is simply a chronic problem with vomiting, diarrhea or both.