Colitis

• Colitis is an inflammation of a dog's colon. The symptoms of colitis can include vomiting, poor appetite, diarrhea, loss of weight and lethargy.
  
  

Inflammatory Bowel Disease

• Inflammatory Bowel Disease has an unknown cause of outbreak in dogs. The symptoms for IBD include a persistent diarrhea and vomiting from your dog because its bowels cannot hold anything.
  
  

Irritable Bowel Syndrome

• Irritable Bowel Syndrome is another bowel disease with unknown causes. Symptoms include softened stools, painful diarrhea, frequent defecation and distended abdomen because of an enlarged bowel.
  
  

Cancer

• Colon cancer is a common disease in dogs. Symptoms of colon cancer can include diarrhea mixed with blood and a strain to defecate.
  
  

Diagnosis

• Most bowel diseases can be diagnosed with a biopsy and blood test. If the bowel is severely infected, the liver and pancreas might also become inflamed, causing the vomiting.