The combination of burps smelling distinctly like rotten eggs alongside diarrhea indicates an issue within the gastrointestinal (GI) tract. The foul odor originates from a gas known as hydrogen sulfide (H₂S). When this gas is produced in excess, it can be expelled through belching, signaling that the gut’s normal balance has been significantly disturbed. Experiencing this alongside loose, watery stools suggests a digestive process that is failing to absorb water properly, pointing toward underlying digestive conditions or infections that require investigation.
Understanding Hydrogen Sulfide Gas
The rotten egg smell is caused by the overproduction of hydrogen sulfide (H₂S) gas by certain microbes residing in the gut. The main precursors for this gas are sulfur-containing compounds found in food, primarily the amino acids cysteine and methionine. Bacteria in the gut ferment these sulfur-rich amino acids, releasing H₂S as a metabolic byproduct. When high levels of H₂S accumulate, this toxic gas can compromise the gut lining and interfere with cell function, potentially contributing to inflammation, and the sheer volume of gas is released through the esophagus, resulting in the characteristic sulfur burp.
Common Conditions that Cause Both Symptoms
The presence of sulfur burps and diarrhea indicates a condition where the normal digestive process is disrupted, leading to both malabsorption and excessive gas production. One of the most common causes is Small Intestinal Bacterial Overgrowth (SIBO), specifically the hydrogen sulfide-dominant type. In SIBO, an abnormally high number of bacteria colonize the small intestine, where they ferment carbohydrates and sulfur-rich proteins before the body can absorb them, leading to both H₂S gas and diarrhea.
Gastrointestinal infections are another frequent culprit, as pathogens like the Giardia parasite or specific bacteria from food poisoning rapidly disrupt the gut flora. These invaders inflame the intestinal lining, impairing its ability to absorb water, which results in diarrhea, while their metabolic activity produces large amounts of H₂S gas. Similarly, an infection with Helicobacter pylori (H. pylori) can contribute to excess gas and digestive distress.
Dietary factors can also overwhelm the system, especially a sudden, large intake of foods high in sulfur compounds like eggs, cruciferous vegetables, or red meat. If the digestive system is compromised, the excess sulfur-rich material travels undigested to the lower gut, providing fuel for H₂S-producing bacteria.
Conditions like Irritable Bowel Syndrome (IBS) or Inflammatory Bowel Disease (IBD) can also feature this symptom profile. The underlying inflammation and motility issues create an environment conducive to gas-producing bacterial activity and altered bowel habits.
Managing Symptoms Through Diet and Lifestyle
While identifying the underlying cause requires a professional diagnosis, several immediate strategies can help manage symptoms. Temporarily reducing the intake of foods known to be high in sulfur can help starve the gas-producing bacteria. This includes limiting items such as:
- Eggs
- Red meat
- Cruciferous vegetables like broccoli and cabbage
- Certain preservatives
Maintaining adequate hydration is important when diarrhea is present, as the body loses significant fluids and electrolytes. Drinking water, diluted fruit juice, or electrolyte solutions helps prevent dehydration. Eating smaller, more frequent meals can ease the digestive burden. Bismuth subsalicylate, for example, is known to interact with H₂S in the gut, which can reduce the gas’s foul odor.
Identifying When Medical Attention is Necessary
While many cases of sulfur burps and diarrhea resolve on their own, medical consultation is necessary if symptoms persist for more than 48 hours. Persistent diarrhea carries a risk of severe dehydration, which is signaled by symptoms like dizziness, lightheadedness, or significantly decreased urination.
Other urgent warning signs include the presence of blood or mucus in the stool, which can suggest an active infection or inflammatory process.
Severe, unrelenting abdominal pain, a high fever, or unexplained weight loss accompanying the sulfur burps and diarrhea also warrant immediate medical attention.