From the Guidelines
Chronic diarrhea is most commonly caused by irritable bowel syndrome (IBS), inflammatory bowel diseases, microscopic colitis, celiac disease, and malabsorption syndromes, as well as infections, medication side effects, endocrine disorders, and food intolerances, as outlined in the most recent guidelines 1. The causes of chronic diarrhea can be broadly categorized into several groups, including:
- Colonic causes, such as colonic neoplasia, ulcerative and Crohn’s colitis, and microscopic colitis, as listed in the guidelines 1
- Small bowel causes, including coeliac disease, Crohn’s disease, and other small bowel enteropathies, as well as bile acid malabsorption and disaccharidase deficiency 1
- Pancreatic causes, such as chronic pancreatitis and pancreatic carcinoma, as well as cystic fibrosis 1
- Endocrine causes, including hyperthyroidism, diabetes, and hormone-secreting tumors, as outlined in the guidelines 1
- Other causes, such as factitious diarrhea, surgical causes, and drug-induced diarrhea, as well as alcohol and autonomic neuropathy, as discussed in the guidelines 1 It is essential to note that the diagnosis of chronic diarrhea requires a comprehensive medical evaluation, including stool tests, blood work, and possibly endoscopic procedures, to determine the underlying cause and guide appropriate treatment, as recommended in the guidelines 1. Key considerations in the diagnosis and management of chronic diarrhea include:
- A detailed history and physical examination to identify potential causes and risk factors, as outlined in the guidelines 1
- Laboratory tests, such as stool tests and blood work, to rule out infections and inflammatory conditions, as recommended in the guidelines 1
- Endoscopic procedures, such as colonoscopy, to evaluate the colon and small bowel, as discussed in the guidelines 1
- Treatment of underlying conditions, such as celiac disease or inflammatory bowel disease, as well as management of symptoms, such as diarrhea and abdominal pain, as outlined in the guidelines 1. In terms of specific causes, bile acid diarrhea (BAD) is a significant consideration in patients with chronic diarrhea, particularly those with a history of cholecystectomy, terminal ileal resection, or radiotherapy, as discussed in the guidelines 1. The diagnosis of BAD can be made using the selenium homocholic acid taurine (SeHCAT) test, which measures the retention of bile acids in the body, as recommended in the guidelines 1. Overall, the management of chronic diarrhea requires a comprehensive approach that takes into account the underlying cause, as well as the patient's symptoms, medical history, and risk factors, as outlined in the guidelines 1.
From the Research
Causes of Chronic Diarrhea
- Inflammatory bowel disease (IBD) 2, 3
- Irritable bowel syndrome (IBS) 4, 2
- Celiac disease 2
- Small intestinal bacterial overgrowth (SIBO) 2
- Bile acid malabsorption 2
- Food intolerance 2
- Motility disorders 2
- Infections, including parasites such as giardia, cryptosporidia, and cyclospora, and bacteria like Yersinia, Plesiomonas, and Aeromonas 5
- Microscopic colitis 3
- Ulcerative colitis 3
- Crohn's disease 3