The human digestive system consists of a series of hollow organs that function to break down large particles of food into small molecules. The mouth, esophagus, stomach, small intestine, large intestine, rectum and anus form the complete digestive tract with the liver, pancreas and gall bladder secreting digestive juices to aid in digestion. The small molecules are absorbed through the wall of the intestines into the bloodstream to provide every cell with nutrients and energy. With so many organs involved, symptoms of a structural or functional disorder vary.
Blood in Stool
Blood in the stool indicates either an injury or a disorder somewhere in the digestive tract. When blood is visible, the color of the blood is important in determining the cause. Stools that appear black or tarry occur when the blood is picked up in the upper portion of the digestive tract, such as the esophagus, stomach or first part of the small intestine. Exposure to digestive juices, such as in the stomach, causes the blood to turn black. The most common cause, according to Medline Plus, is the presence of a stomach ulcer.
Dark red or bright red stools indicate a problem in the large intestine, rectum or anus. Diverticulosis, abnormal pockets along the membrane of the large intestine, causes lower digestive tract bleeding. Hemorrhoids, swollen veins in the anus or rectum, cause bleeding around the anus that can affect the color of stools.
Severe Abdominal Pain
Abdominal pain refers to pain felt anywhere in the region from the chest to the groin. Information provided by Medline Plus indicates that the severity of the abdominal pain does not necessarily indicate the seriousness of the condition causing it. Mild conditions such as gas or viral gastroenteritis--which is inflammation of the stomach or intestines caused by a viral infection--can cause severe abdominal pain. Many digestive disorders cause abdominal pain. This includes heartburn, chronic constipation, bowel blockage, irritable bowel syndrome and stomach ulcers.
Change in Bowels
The body typically regulates itself to perform daily functions, such as bowel function, at approximately the same time each day. Anytime a change in bowel habits occurs, such as a change in consistency or frequency, a digestive disorder may be to blame. The onset of constipation or diarrhea may signal the onset of disorders such as irritable bowel disease, Crohn's disease, diverticulitis or cancer affecting an organ of the digestive tract.
Unintentional Weight Loss
Body weight is affected not only by the number of calories taken in but also by overall health, age and the ability of the digestive tract to absorb the nutrients. Digestive disorders, such as Crohn's disease, ulcerative colitis or celiac disease, interfere with the ability of the small intestines to absorb nutrients. When the body cannot absorb digested food particles, weight loss occurs. If temporary, the weight loss may be a welcomed event. If it persists, or if 5 percent of the total body weight is lost, it could be sign of an underlying condition, according to the Mayo Clinic.
