Chronic Diarrhea Normal Abnormal Diarrhea is defined as loose, watery, or more frequent stool than normal. Chronic Diarrhea-a state of persistent Diarrhea that may be ongoing for weeks, months, or years-stems from various causes. Listed below are general categories with brief descriptions of each. Osmotic -- substances that are capable of drawing water (i.e., osmotically active) are present in the stool, forcing water from the intestines to be excreted, resulting looser stools. Bloating and flatulence (gas) often occur. Common causes include lactose deficiency, use of Magnesium-containing laxatives, use of sorbitol in dietetic foods, use of the fat substitute olestra. A rare cause often missed is Celiac Sprue disease (caused by the gluten in wheat) Irritable Bowel Syndrome -- characterized by abdominal pain, distention, and stool with mucous. See section on Irritable Bowel Syndrome. Inflammatory conditions -- a disease process causes an inflammatory reaction in the intestines. Symptoms include weight loss, blood in the stool, abdominal distention/pain, and fever. Common causes include Crohn's Disease and ulcerative colitis. Obstructive lesions -- colon or Rectal Cancers may present (i.e., reveal symptoms) as slowly worsening Diarrhea syndromes. Stools may be narrow and the abdomen bloated. The patient will likely feel constipated, due to the inability to evacuate. Malabsorption -- certain foods cannot be absorbed properly and are passed into the stool, resulting in Diarrhea in an attempt to excrete them. Symptoms include those of osmotic Diarrhea (since it acts like one), weight loss, and nutritional deficiencies. Causes include bacterial overgrowth, chronic pancreatitis (pancreas fails to produce the enzymes needed to breakdown food), previous intestinal resections (part of the intestine surgically removed), and lymphatic obstruction. Motility disorders -- occurs as a result of too rapid a transit of intestinal materials, allowing insufficient time for food/water to be absorbed. Diabetes, Hyperthyroidism, and other systemic illnesses are often the cause. Secretory conditions -- an abnormal secretion of water in the intestine, resulting in Diarrhea. Causes include laxative abuse, endocrine tumors, and bile salt malabsorption. Chronic Infections -- caused by parasites such as Giardia or amebiasis. Patients with AIDS are susceptible to many infections. Microsporidium is classic in AIDS patients, but there are multiple possible causes. Factitial-self -- induced Diarrhea or pretending to have Diarrhea. Causes include laxative abuse and adding liquid to stool. A careful history and physical examination -- travel, food intolerances, etc., may give clues. Stool tests: stool checked for -- Fecal leukocytes Ova & parasites Stool osmolality 24-hour stool collection for weight and fecal fat Stool laxative screen Blood Tests: Complete blood count, thyroid function tests, Electrolytes, Calcium, Phosphorus, albumin, and liver function tests. Beta-carotene and Prothrombin time may be helpful. More advanced testing would include urinary 5-HIAA (to rule out Carcinoid Syndrome), Cortisol (rule out Addison's Disease), VIP (rule out VIPoma), gastin level (rule out Zollinger-Ellison Syndrome) and Calcitonin (rule Medullary Thyroid Cancer). Diagnostic testing: Colonoscopy can check for inflammatory bowel conditions and cancer Upper endoscopy can be used to biopsy for malabsorption Proctoscopy (scope placed in rectum only) -- may detect inflammatory bowel disease; show signs of anthraquinone laxatives or Rectal Cancer. Plain X-Rays of the abdomen may reveal a calcified pancreas (chronic pancreatitis) or show lesions suggestive of colon cancer. Abdominal CT scans -- may show chronic pancreatitis, colon cancer, and signs of Crohn's Diseases (ileitis) or pancreatic endocrine tumors. Treat the underlying cause, e.g., lactose deficiency (dietary restriction on dairy products). (See specific conditions for details.) General treatment: Loperamide (Immodium) Diphenoxylate with atropine (Lomotil) Codeine, tincture of opium, and paregoric  -- only used in extreme conditions, as very addicting Cholestyramine -- good for treating those with Diarrhea from an intestinal resection or ileal (part of the small intestine) disease Octreotide -- used for Carcinoid Syndrome and VIPomas Clonidine patch -- may help with some secretory Diarrheas, Diarrhea due to diabetes, and cryptosporidium See your physician as soon as possible.