Upper abdominal pain and black, tarry stool are warning signs of many dangerous diseases. Therefore, patients need to be very cautious with these symptoms and should go for medical check-ups for accurate diagnosis and timely treatment.

Gastric mucositis is a condition in which the lining of the stomach (also known as the gastric mucosa) becomes inflamed, irritated, and eroded. It occurs when the protective layer of the stomach is damaged.