Chronic Diarrhea in Adults: Evaluation and Differential Diagnosis.

Chronic diarrhea is defined as a predominantly loose stool lasting longer than four weeks. A patient history and physical examination with a complete blood count, C-reactive protein, anti-tissue transglutaminase immunoglobulin A (IgA), total IgA, and a basic metabolic panel are useful to evaluate for pathologies such as celiac disease or inflammatory bowel disease. More targeted testing should be based on the differential diagnosis. When the differential diagnosis is broad, stool studies should be used to categorize diarrhea as watery, fatty, or inflammatory. Some disorders can cause more than one type of diarrhea. Watery diarrhea includes secretory, osmotic, and functional types. Functional disorders such as irritable bowel syndrome and functional diarrhea are common causes of chronic diarrhea. Secretory diarrhea can be caused by bile acid malabsorption, microscopic colitis, endocrine disorders, and some postsurgical states. Osmotic diarrhea can present with carbohydrate malabsorption syndromes and laxative abuse. Fatty diarrhea can be caused by malabsorption or maldigestion and includes disorders such as celiac disease, giardiasis, and pancreatic exocrine insufficiency. Inflammatory diarrhea warrants further evaluation and can be caused by disorders such as inflammatory bowel disease, Clostridioides difficile, colitis, and colorectal cancer.

Care of the Colorectal Cancer Survivor.

Colorectal cancer is the fourth most common cancer in the United States and has a five-year survival rate of 65%. The American Cancer Society and other experts have released guidelines on surveillance, health promotion, screening for other malignancies, and management of treatment effects. Surveillance for disease recurrence should occur every three to six months for the first two to three years, then every six months for a total of five years. Each visit should include a history and physical examination, routine care for chronic medical conditions, and screening for other primary cancers according to guidelines for the general population. Topics addressed depend on the treatment utilized but generally include gastrointestinal issues, neuropathy, pain, urinary symptoms, fatigue, psychological issues, cognitive problems, sexual symptoms, and stoma care. Carcinoembryonic antigen testing should be performed at each visit in patients who are candidates for further intervention. Chest, abdomen, and pelvic computed tomography should be performed annually for five years after treatment. Colonoscopy should be repeated one year after treatment, then three years later if no advanced adenoma is identified.

Esophageal Cancer.

Esophageal cancer has a poor prognosis and high mortality rate, with an estimated 16,910 new cases and 15,910 deaths projected in 2016 in the United States. Squamous cell carcinoma and adenocarcinoma account for more than 95% of esophageal cancers. Squamous cell carcinoma is more common in nonindustrialized countries, and important risk factors include smoking, alcohol use, and achalasia. Adenocarcinoma is the predominant esophageal cancer in developed nations, and important risk factors include chronic gastroesophageal reflux disease, obesity, and smoking. Dysphagia alone or with unintentional weight loss is the most common presenting symptom, although esophageal cancer is often asymptomatic in early stages. Physicians should have a low threshold for evaluation with endoscopy if any symptoms are present. If cancer is confirmed, integrated positron emission tomography and computed tomography should be used for initial staging. If no distant metastases are found, endoscopic ultrasonography should be performed to determine tumor depth and evaluate for nodal involvement. Localized tumors can be treated with endoscopic mucosal resection, whereas regional tumors are treated with esophagectomy, neoadjuvant chemotherapy, chemoradiotherapy, or a combination of modalities. Nonresectable tumors or tumors with distant metastases are treated with palliative interventions. Specific prevention strategies have not been proven, and there are no recommendations for esophageal cancer screening.