Diarrhea Causes

Shigella flexneri

A 12-year-old boy presents with a 1-week history of sudden-onset watery diarrhea while visiting relatives in Dakar, Bangladesh. There he ate mostly vegetables at a local market. On his return to the US, he developed abdominal cramps, fever, bloody diarrhea, and a feeling of incomplete defecation. Bowel movements are accompanied by pain, cramping, and straining. He has about 10-12 bowel movements per day, productive of mucoid bloody stool that is small in quantity. He is febrile, with a temperature of 101.2°F (38.5°C). The mucous membranes are dry, and there is reduced skin turgor; his pulse is 100 beats/minute, and BP is 110/70 mmHg with a 10 mmHg postural drop.

Salmonella enteritidis

A 14-year-old boy presents with nausea, vomiting, and diarrhea. Two days ago, he had been at a picnic where he ingested undercooked chicken along with a variety of other foods. He reports moderate-volume, non-bloody stools occurring 6 times a day. He has mild abdominal cramps and a low-grade fever. He is evaluated at an acute care clinic and found to be mildly tachycardic (heart rate 105 bpm) with a normal BP and a low-grade temperature of 100.1°F (37.8°C). His physical exam is unremarkable except for mild diffuse abdominal tenderness and mild increased bowel sounds. He is able to take oral fluids and is instructed on the appropriate oral fluid and electrolyte rehydration. One week later he develops redness and irritation of the eyes, painful knees, and burning with urination.

Campylobacter jejuni

A 16-year-old boy presents with abdominal pain and diarrhea. Two days earlier, he attended a picnic where he ate undercooked chicken. He has been having about 8 bowel movements a day of moderate-volume diarrhea with no gross blood. He has severe abdominal cramping, a low-grade fever, and mild tachycardia. His physical examination is unremarkable except for abdominal tenderness, which is most significant in the right lower quadrant.

Escherichia coli

A 22-year-old American student develops severe cramping and watery stools 3 days after arriving in Guatemala. Although she avoided salads and tap water, she did drink some local passion fruit juice with crushed ice before becoming ill. Frequent episodes of diarrhea keep her confined to her hotel room. She is afebrile. She has no underlying health problems and recovers 3 days later. Her recovery is uneventful except for several days of fatigue.

Crohn's disease

A 25-year-old white man presents to his primary care physician with intermittent abdominal cramping and watery diarrhea for 3 months. He reports fatigue and losing 15 lbs (6.8 kg) during this period. On physical exam, his temperature is 99.6ºF (37.6ºC). Other vital signs are within normal limits. Abdomen is soft with normal bowel sounds and moderate tenderness in the right lower quadrant, without guarding or rigidity. Rectal exam reveals perianal skin tags. The stool is guaiac positive. Colonoscopy reveals ileitis.

Lactase deficiency

A 25-year-old woman presents with diarrhea, bloating, abdominal pain, and flatulence that occur after consuming dairy products. Abdominal exam reveals a slightly distended abdomen. Stool is negative for occult blood.

Ulcerative colitis

A 27-year-old man with a 3-month history of rectal bleeding and diarrhea is referred for evaluation. Laboratory tests show mild anemia, an elevated sedimentation rate, and the presence of white blood cells in stool. Stool culture is negative. Colonoscopy shows continuous active inflammation with loss of vascular pattern and friability from the anal verge up to 35 cm, with a sharp cut-off. The colonic mucosa above 35 cm appears normal, as does the terminal ileum.

Vibrio cholerae

A 3-year-old boy is brought to the health post in a rural Zimbabwean village by his distraught mother. The child started to have diarrhea 20 hours ago, and the volume has increased rapidly, so that now there is almost a continuous passage of thin yellow stools into the bed. Initially the child was taking fluids but is now drowsy and unresponsive. On examination, the radial pulse is impalpable, blood pressure is unrecordable, and the eyes are sunken. Skin turgor is poor. The mother notes that the child has not urinated for 12 hours. The mother also reports that several members of her family and others in the village are also ill with a similar illness and that 3 children have already died.

Giardia lamblia

A 32-year-old man returning from a visit to rural India presents with a 2-week history of frequent but small-volume, greasy, foul-smelling, yellowish stools with tendency to float. Patient admits to camping and drinking water from a freshwater stream while on the trip. His male sexual partner has also developed bloating symptoms for the past 2 days. Other complaints include nausea, frequent belching with a sulfuric smell, abdominal bloating, and flatulence. Only positive finding on physical exam is mild distention of abdomen with no tenderness, masses, or organomegaly.

Irritable bowel syndrome

A 34-year-old woman presents to her family physician with a 12-week history of intermittent abdominal cramping in her lower abdomen. She alternates between being constipated and having diarrhea. Diarrhea is characterized by frequent small, soft stools accompanied by mucus but no blood. Her abdominal pain is improved with bowel movement or passage of flatus. Past medical history is unremarkable. Family history is negative for colon cancer. A sister has similar symptoms but has not seen a physician. Personal/social history reveals that she is an accountant working long hours. Her firm is about to merge with another, and she fears her job situation is tenuous. Review of systems is otherwise negative. She has not lost any weight or had any other constitutional symptoms. Physical examination reveals no abdominal tenderness or mass. Stool is guaiac negative.

Hyperthyroidism

A 38-year-old woman, who in the past had tried to lose weight without success, is happy to see that in the last 2 months she has lost 25 pounds. She also has difficulty sleeping at night. Her husband complains that she is keeping the house very cool. She recently consulted her ophthalmologist because of redness and watering of the eyes. Eye drops were not helpful. She consults her doctor for fatigue and anxiety, palpitation, and easy fatigability. On physical examination, her pulse is 100/minute and her blood pressure is 150/95 mm Hg. The conjunctivae are red and she has a stare.

Clostridium perfringens

A 40-year-old woman develops abdominal cramping and watery diarrhea 12 hours after eating undercooked chicken. She is afebrile and has no nausea or vomiting. Inspection of leftover chicken reveals numerous gram-positive rods.

Staphylococcus aureus

A 40-year-old woman develops nausea, explosive vomiting, and abdominal cramping followed by watery diarrhea 4 hours after eating an undercooked hamburger. She is afebrile.

Bacillus cereus

A 40-year-old woman develops nausea, vomiting, and abdominal cramping 6 hours after eating reheated rice from a Chinese restaurant. She is afebrile and has no diarrhea. Inspection of leftover rice reveals numerous gram-positive rods.

Chronic pancreatitis

A 41-year-old alcoholic man has a 6-year history of recurrent attacks of pancreatitis characterized by epigastric pain radiating to the back. The initial attack required hospitalization for severe pain, and clinical chemistry showed a >15-fold elevation in serum amylase and lipase. Subsequent attacks were less severe, managed primarily as an outpatient, and lasted less than 10 days, with long symptom-free intervals. After detoxification 6 months ago he had no further attacks, but has recently developed diabetes and diarrhea, characterized by loose, greasy stools that float on the surface. CT imaging shows pancreatic calcifications but no cystic or mass lesions.

Cryptosporidium parvum

A 41-year-old man with HIV infection complains of persistent watery diarrhea that has lasted several months. He has noted no blood in his stools but has lost weight. He has not been taking highly active antiretroviral therapy (HAART) and his CD4 lymphocyte count is 48/mm3.

Zollinger-Ellison syndrome

A 45-year-old male presents with abdominal pain, diarrhea, and heartburn. Physical exam is unremarkable. On endoscopy he is found to have multiple gastric and duodenal ulcers. The patient is prescribed proton-pump inhibitors and treated for Helicobacter pylori, which relieves his symptoms temporarily. However, he has multiple recurrences of symptoms and ulcers.

Celiac disease

A 46-year-old woman presents with fatigue and is found to have anemia due to iron deficiency. She has had intermittent episodes of diarrhea for many years. Often her stools are loose, greasy, malodorous, and voluminous. She has lost 15 lbs in the past 6 months. Examination reveals two ulcers in the mouth and a blistering rash on her back that was identified by her dermatologist as dermatitis herpetiformis. Abdominal examination is normal and the stool is negative for occult blood.

VIPoma

A 59-year-old woman presents with a 3-month history of profuse watery diarrhea, weakness, and dehydration accompanied by spells of flushing and low blood pressure. Examination reveals poor skin turgor. Blood tests show a serum potassium level of 2.1 mEq/L, calcium level of 11.2 mg/dL, and glucose level of 180 mg/dL.

Rotavirus

A 6-month-old boy presents with a history of low-grade fever of 100°F (37.7°C) and vomiting (6 episodes per day) for 2 days. This is followed by diarrhea severe (15 stools per day) 24 hours later. Stools are watery and do not contain blood or mucus. His mother is unsure of the urine output but the infant has lost 1.5 lb of weight in the past few days. His mother also reports that the infant is more irritable and has decreased activity level since the onset of the illness. He attends a daycare center. His 2-year-old brother who attends the same daycare center has just got over a bout of "stomach flu."

Carcinoid

A 60-year-old man presents with a 3-year history of diarrhea, with no clear precipitating factor. Over the past few months he has noticed intermittent flushing of his face. These episodes occur at any time but are worse during times of stress and exercise. His wife has also noticed intermittent reddening of his face, which lasts for a few minutes. He also describes occasional wheezing and mild peripheral edema. He feels worse when he consumes alcohol, chocolate, and bananas.

Medication

A 68-year-old man with gastroesophageal reflux develops diarrhea after starting omeprazole.

Clostridium difficile

A 72-year-old white man presents with a 5-day history of abdominal pain, nausea, severe diarrhea, fever, and malaise. He was started on levofloxacin for community-acquired pneumonia 2 weeks prior with resolution of his pulmonary symptoms. Exam reveals a fever of 101°F (38.3°C) and mild abdominal distension with minimal tenderness. Laboratory tests reveal a peripheral WBC of 12,000/mm3 and stool guaiac that is positive for occult blood.

Norovirus

Twelve people of get sick on a cruise ship. Symptoms include fever, malaise, headache, muscle aches, nausea, vomiting, watery diarrhea, abdominal pain, and loss of taste.