Pylorus stenosis is a condition that a child under one year may have. The connection between the stomach and the intestine does not work properly, but the food is prevented from entering the intestine.
Stomach pain can have many causes. Read about them here, as well as the problems and diseases of the esophagus and stomach.
You can get a stomach ache for many reasons. The cause can be obvious, for example in case of food poisoning or menstrual pain. Sometimes it is more difficult to know what it is due to, for example if the problems are about stress or a disease that is difficult to detect. Often, stomach pain goes away by itself but sometimes you may need treatment.
It is very common for children to have stomach ache. Children may have a stomach ache for many different reasons, but usually it is not dangerous. Often stomach pain goes away by itself, but sometimes the child may need treatment.
Gastric ulcer means that ulcers have formed in the lining of the stomach or duodenum. Most people with stomach ulcers get stomach upset, usually in the middle of the upper part of the stomach. Stomach ulcers are usually caused by a bacterium, but even some medications can cause stomach ulcers. Most people become good at treatment.
Between the stomach and the esophagus is the upper stomach. If it does not hold tightly, the contents of the stomach can be pushed up into the esophagus. It is called gastroesophageal reflux. If the stomach contents that are upset affect the child negatively, it is called gastroesophageal reflux disease.
Dyspepsia is the collective name for various symptoms that you may have in the upper abdomen. For example, you may feel sore or have a burning sensation in the stomach. Dyspepsia may be due to a disease, but most often the doctor does not find any cause for dyspepsia. Dyspepsia is therefore often called a sensitive stomach.