Diarrhoea is one of the most frequent gastrointestinal complaints worldwide, affecting millions of adults every year. Though often temporary and mild, it can sometimes indicate more serious underlying health issues. Understanding the common causes of diarrhoea in adults is crucial for effective treatment, prevention, and, when necessary, seeking medical attention.
What Is Diarrhoea?
Diarrhoea is characterised by the passage of loose, watery stools at an increased frequency — typically three or more times per day. It can be acute, lasting a few days, or chronic, persisting for more than four weeks. Diarrhoea results from disruptions in the normal absorption and secretion balance within the intestines.
Nitazoxanide 500 mg is an effective treatment for diarrhoea caused by infections. Buy it online safely and conveniently on Dosepharmacy for fast relief and trusted quality at your doorstep.
Why Does Diarrhoea Occur?
The intestines normally absorb water and nutrients from food while secreting mucus and electrolytes. Diarrhoea occurs when:
-
The intestines secrete more fluids than they absorb (secretory diarrhoea)
-
Food moves too quickly through the intestines (motility-related diarrhoea)
-
The intestinal lining is inflamed or damaged (inflammatory diarrhoea)
-
Osmotic substances pull water into the intestines (osmotic diarrhoea)
Understanding the causes helps target treatment effectively.
1. Infections: The Leading Cause of Acute Diarrhoea
The most common cause of diarrhoea in adults worldwide is infection by viruses, bacteria, or parasites.
Viral Infections
Viruses like norovirus, rotavirus, and adenovirus are frequent culprits, especially in outbreaks and among travelers. These viruses invade the intestinal lining, disrupting absorption and causing watery diarrhoea often accompanied by nausea, vomiting, and fever.
Bacterial Infections
Bacterial pathogens such as Escherichia coli (E. coli), Salmonella, Shigella, and Campylobacter can cause diarrhoea through toxins that irritate the intestines or through direct invasion of the gut wall. These often result from consuming contaminated food or water.
Parasitic Infections
Parasites like Giardia lamblia, Entamoeba histolytica, and Cryptosporidium can cause prolonged diarrhoea, particularly in travelers or those with weakened immune systems.
Key Insight: Infectious diarrhoea is usually self-limiting but requires hydration and sometimes antibiotics or antiparasitic medications.
2. Food Intolerances and Allergies
Many adults experience diarrhoea as a reaction to certain foods or ingredients that their digestive systems cannot process properly.
Lactose Intolerance
A deficiency of the enzyme lactase leads to the inability to digest lactose, a sugar found in dairy products. Undigested lactose ferments in the colon, drawing water into the intestines and causing diarrhoea, bloating, and gas.
Fructose and Sorbitol Intolerance
Similar to lactose intolerance, some adults struggle to absorb fructose (a sugar in fruits) or sorbitol (a sugar alcohol in sugar-free products), which leads to osmotic diarrhoea.
Food Allergies
Though less common, true food allergies can trigger diarrhoea along with other symptoms such as hives, swelling, or anaphylaxis.
Management: Identifying and avoiding trigger foods is essential for controlling diarrhoea caused by food intolerances.
3. Medications and Medical Treatments
Several medications can cause diarrhoea as a side effect by altering the balance of intestinal flora or irritating the gut lining.
Antibiotics
Antibiotics disrupt the normal gut microbiota, sometimes allowing overgrowth of harmful bacteria like Clostridium difficile (C. diff), which causes severe diarrhoea and colitis.
Other Drugs
Medications including antacids containing magnesium, laxatives, chemotherapy drugs, and some heart medications can also cause diarrhoea.
Medical Procedures
Radiation therapy targeting the abdomen or pelvis often damages the intestines, leading to radiation enteritis and diarrhoea.
4. Chronic Gastrointestinal Diseases
When diarrhoea lasts longer than four weeks, chronic gastrointestinal diseases are often the cause.
Irritable Bowel Syndrome (IBS)
IBS is a functional disorder characterised by abdominal pain and changes in bowel habits, including diarrhoea-predominant IBS. The exact cause is unknown but involves altered gut motility, heightened sensitivity, and possibly gut-brain axis dysfunction.
Inflammatory Bowel Disease (IBD)
IBD includes Crohn’s disease and ulcerative colitis, conditions marked by chronic inflammation of the gut lining, which leads to persistent diarrhoea, sometimes with blood or mucus.
Celiac Disease
An autoimmune disorder triggered by gluten ingestion, celiac disease causes inflammation and damage in the small intestine, leading to malabsorption and diarrhoea.
5. Malabsorption Syndromes
Conditions that impair nutrient absorption can cause osmotic diarrhoea.
-
Pancreatic insufficiency: The pancreas fails to secrete enough digestive enzymes, leading to fatty stools and diarrhoea.
-
Short bowel syndrome: Surgical removal of portions of the intestine reduces the absorption surface area.
-
Bile acid malabsorption: Excess bile acids entering the colon can stimulate secretion and motility, causing diarrhoea.
6. Stress and Lifestyle Factors
Emotional stress and lifestyle habits can influence bowel function and trigger diarrhoea episodes.
-
Stress and anxiety can increase gut motility and sensitivity.
-
Excessive caffeine, alcohol, and artificial sweeteners can irritate the gut.
-
Sudden dietary changes, especially when travelling, can cause “traveller’s diarrhoea.”
7. Other Causes
-
Endocrine disorders like hyperthyroidism and diabetes can alter bowel habits.
-
Cancer affecting the gastrointestinal tract.
-
Surgical complications from bowel surgeries.
When to See a Doctor
Most diarrhoea resolves on its own, but urgent medical attention is needed if you experience:
-
Severe dehydration symptoms (dizziness, dry mouth, dark urine)
-
Blood or pus in the stools
-
Persistent diarrhoea lasting more than 2 days (acute) or 4 weeks (chronic)
-
High fever
-
Unexplained weight loss
Diagnosis and Treatment
A doctor will typically diagnose the cause through:
-
Medical history and symptom review
-
Stool tests for infection or blood
-
Blood tests for inflammation or malabsorption
-
Imaging or endoscopy for chronic conditions
Treatment depends on the cause:
-
Rehydration therapy is key for all diarrhoea.
-
Antibiotics or antiparasitics for infections.
-
Dietary changes for intolerances.
-
Medications like anti-inflammatory drugs or immunosuppressants for IBD.
-
Probiotics may help restore gut flora.
Prevention Tips
-
Practice good hygiene and handwashing
-
Drink safe, clean water
-
Avoid risky foods, especially when travelling
-
Manage stress
-
Follow prescribed medication guidelines
Conclusion
Diarrhoea in adults can stem from many causes, ranging from infections and food intolerances to chronic illnesses. Recognizing the common causes is vital to choosing the right treatment and when to seek medical care. With proper care, most cases resolve quickly, allowing you to return to good health.
wasishah
clinic55
bisma21