Your bowels, also called the large intestine, are the lower parts of digestive system. Once your intestines finishes the process of digesting food you would want to visit the toilet for clearing your bowels. Bowel can be just a day once for some, and three times in a day for others. But that can be called be normal according to their body type. Normal bowel would be soft, brownish in colour and should be able to pass without pain.
There can be two kinds of problems in your bowel movement:
Constipation: This is when the stools are hard, thick, rough texture and painful to pass out. This may be due to less intake of water, less fiber rich food in the diet, irregular eating habits, less sleep etc. There might be many medical reasons for it which has be treated.
Diarrhea: Commonly called loose stools. The bowel would work faster during this time and the stools texture would be liquid and stick. This is mainly due to infections. There are chances that one can be nauseated. This has to be treated by a doctor as it may turn out to be a little serious problem.
Exercise and diet have to be done for a good bowel movement. Due to stress you're eating habits change and thus can lead to bad bowel movement. Long term bowel problems can lead to irritable bowel syndrome.
Talk to your doctor and dietitian to help your child to have healthy bowels.