Approach to the adult patient with chronic diarrhea: A literature review

Chronic diarrhea is defined by symptoms lasting longer than 4 weeks. It is a common problem that affects up to 5% of the adult population. Different pathophysiologic mechanisms involve numerous causes, including drug side effects, postoperative anatomic and physiologic alterations, intestinal and colonic wall abnormalities, inflammatory or malabsorption causes, pancreatobiliary diseases, and functional or gut-brain axis disorders associated with dysbiosis or gastrointestinal motility alterations. Due to such a broad differential diagnosis, it is important to categorize chronic diarrhea into five main groups: drug side effect, postoperative, postinfectious, malabsorptive, inflammatory, and functional. The present review is a narrative analysis of the diagnostic approach, emphasizing key aspects of the clinical history, the utility of biomarkers (in breath, stool, urine, and serology) and malabsorption and motility tests, the role of radiologic and endoscopic studies, and the most common histologic findings. A diagnostic algorithm aimed at determining etiology and personalizing therapy is also proposed.

Approach to the adult patient with chronic diarrhea: a literature review

Chronic diarrhea is defined by symptoms lasting longer than 4 weeks. It is a common problem that affects up to 5% of the adult population. Different pathophysiologic mechanisms involve numerous causes, including drug side effects, postoperative anatomic and physiologic alterations, intestinal and colonic wall abnormalities, inflammatory or malabsorption causes, pancreatobiliary diseases, and functional or gut-brain axis disorders associated with dysbiosis or gastrointestinal motility alterations. Due to such a broad differential diagnosis, it is important to categorize chronic diarrhea into five main groups: drug side effect, postoperative, postinfectious, malabsorptive, inflammatory, and functional. The present review is a narrative analysis of the diagnostic approach, emphasizing key aspects of the clinical history, the utility of biomarkers (in breath, stool, urine, and serology) and malabsorption and motility tests, the role of radiologic and endoscopic studies, and the most common histologic findings. A diagnostic algorithm aimed at determining etiology and personalizing therapy is also proposed.

[Ipilimumab-induced colitis: A new challenge for gastroenterologists]

Many drugs can produce enterocolitis and they should always be included in the differential diagnosis of this clinical picture. Entities such as antibiotic-associated colitis and neutropenic colitis have been known for some time and recently a new type of drug-induced colitis has emerged due to monoclonal antibodies. Ipimumab is a humanized monoclonal antibody against the CTLA4 molecule that is involved in the maturation and regulation of T lymphocyte activation. This drug causes immune activation and has an immune-mediated antitumor effect with excellent results in tumours such as melanoma. However, several immune-related adverse effects may occur in different organs. The most frequently involved site is the gastrointestinal tract, with adverse effects ranging from mild diarrhoea to colitis with systemic involvement, intestinal perforation, and even death. Although no similarities have been found in the pathogenesis with inflammatory bowel disease, treatments have been used in correlation with its autoimmunological profile: anti-TNF alpha corticosteroids have shown clinical efficacy in moderate to severe disease. However the use of anti-TNF treatment has not been defined and the safety profile is unknown. The inclusion of these new therapies in the treatment of several tumours requires familiarity with these entities and their management should be approached as a new challenge for the gastroenterologist. For that reason, we conducted a review of ipilimumab-induced colitis, evaluating essential features of its symptoms, diagnosis and treatment.