While symptoms of intestinal diseases vary by condition, common gastrointestinal symptoms include indigestion, heartburn, nausea, constipation and bloating, explains American College of Gastroenterology. Others include flatulence, belching, abdominal pain, vomiting and diarrhea. Irritable bowel syndrome, one of the most commonly diagnosed gastrointestinal disorders, has symptoms including mucus in the stool, bloating, bowel movement irregularities, excessive gas, and lower-belly pain that usually subsides following a bowel movement, notes WebMD.
Inflammatory bowel diseases are also among the commonly diagnosed intestinal diseases, according to WebMD. The two types of inflammatory bowel diseases are Crohn's disease and ulcerative colitis. Both conditions have symptoms including diarrhea, reduced appetite, unintentional weight loss, bloody stool and abdominal pain, describes Mayo Clinic. Patients with these diseases also commonly experience low-grade fevers and fatigue.
Doctors further classify ulcerative colitis into several categories depending on symptom severity and the location of the inflammation, notes Mayo Clinic. Ulcerative proctitis, in which inflammation occurs near the rectum, is the mildest form and may have rectal bleeding as its only symptom. Proctosigmoiditis involves inflammation in both the rectum and the lower colon, and it has symptoms including inability to pass bowels, bloody diarrhea and abdominal cramping. Pancolitis is the form in which the entire colon is inflamed, producing severe episodes of bloody diarrhea, severe weight loss, stomach pain and fatigue. Acute severe ulcerative colitis is the rarest type and causes patients to be unable to eat and experience severe diarrhea and pain, bleeding and fevers.