Stomach worms are common and can cause various symptoms like diarrhea, stomach pain, and blood in stool. Worms can infect other parts of the body and cause serious complications if they move from the stomach. Common causes of worm infections include dirty environment, unsafe food, and poor hygiene. Doctors examine patients and conduct tests to identify the type of worm infection. Most infections are treated with anti-parasitic medicines prescribed by doctors. Maintaining cleanliness and proper hygiene can help prevent worm infections.