General SIBO-Symptoms:
Bloated abdomen ('like pregnant') with or without flatulence
Abdominal pressure, pain or cramps in the upper or whole abdomen
Changing stools (sometimes diarrhea, sometimes constipation)
Acidic/painful stools or fatty stools (shiny, foul-smelling stools floating on the surface of the water)
Intense tiredness
Unclear weight fluctuations
Bowel sounds
Fluctuating intolerances (sometimes complaints, sometimes none)
I have no idea what I can and can't tolerate.
I feel best when I don't eat anything.
I can't tolerate fat well.

Hydrogen SIBO (H2-SIBO):
Diarrhea (mushy to watery)
Feeling hungry despite regular meals
I feel best in the morning.
My symptoms get worse during the day, especially in the evening/at night.
Symptoms occur within 2 hours after eating.
Bread, pasta, dough or legumes cause discomfort.

Intestinal Methanogen Overgrowth (IMO):
Constipation
Incomplete emptying
Loss of appetite
Quick feeling of fullness
Nausea or vomiting
Air regurgitation, acid regurgitation or reflux
Feeling that food stays in your stomach for many hours.
Symptoms are present from morning to evening.

Intestinal Hydrogen Sulfide Overproduction (ISO):
Diarrhea
Metal taste in the mouth or bad breath
Anxiety, mood swings, depression
Tingling, itching or numbness in the legs, hands, fingers
Body aches, feeling ill or as if poisoned
Flatulence that smells of sulphur (like rotten eggs)
Protein-rich foods, meat, eggs, garlic, onions cause discomfort
Worsening of intolerances such as sulphur, histamine and salicylate intolerance ('aspirin allergy', chronic nasal congestion)
Unfavorable reactions to Epsom salt bath; glucosamine, glucosamine sulfate or MSM

Small Intestine Fungal, Mold or Yeast Overgrowth (SIFO):
White coating on the tongue
Unintentional weight loss
Taking immunosuppressants/steroids or antibiotics
Chemotherapy
Tinnitus
Digestive enzymes are poorly tolerated or do not work
Increased craving for sweets
Leads to symptoms: Sweets, beer, prosecco, kombucha, yogurt, pickles, sauerkraut or lactose-free cow's milk.

Permeable bowel (leaky gut or intestinal mucosal dysfunction), Lactobacillus resistance and histamine problems:
Drowsiness, 'brain fog', forgetfulness, concentration problems
Headache, migraine
Nausea
Dizziness
Tense neck
Muscle and/or joint pain
Dry skin, skin rashes, acne
Hair loss
Menstrual cramps
Cardiac arrhythmia
Low blood pressure
Increased pulse
Breathing difficulties
Blocked/runny nose
Sweating at night or in the morning
Sleep disorders
I react to alcohol.
I react to reheated meals and or eating out.
I am very sensitive to food ingredients, E-numbers, food supplements and medication.
I cannot tolerate many foods

Cause and risk factors I: Slow small intestine activity
Chronic constipation
Chronic stress
Parasites
Food poisoning or post-infectious irritable bowel syndrome
Infections: General infections, intestinal infections, acute/infectious gastrointestinal inflammation, COVID, Lyme disease, mononucleosis (EBV), varicella zoster

Drugs and addictive substances:

Chronic diseases:

Age: Older than 75 years
Accidents: traumatic brain, head, pelvic floor or spinal column injury, whiplash, skiing or riding accident - head injury not necessary
Operations: in the brain, spine, uterus or gastrointestinal tract

Cause and risk factors II: Altered intestinal anatomy
Dysfunction of the ileocecal valve or reduction in ileocecal pressure (ICJP) in celiac disease, Lyme disease or inflammation in the ileum
Removal of the ileocecal valve
Adhesions after operations
Blind loop syndrome in case of hernia, small bowel diverticulum or Crohn's disease
Narrowing (stenosis) in Crohn's disease or tumor
Pressure formation (compression) in endometriosis, tumor or the small bowel vascular disease 'superior mesenteric artery syndrome'
Twisting of the small intestine (twist/volvulus)
Unwanted connection between two organs (fistula) such as the large and small intestine or in Crohn's disease

Causes and risk factors III: Others
Reduced stomach acid: Long-term therapy with gastric acid protectors, gastritis with or without Helicobacter pylori, reduction/removal of the stomach, hormonal inhibition due to a pancreatic tumor (VIPoma)
Less digestive juices: acute pancreatitis, chronic pancreatic insufficiency, removal of the gallbladder, less pancreatic and bile juices due to reduced stomach acidity
Weakened immunity: Immunosuppressants (e.g., Imurek, Humira, Remicade, Stelara, Xolair), HIV, IgA deficiency, restless legs syndrome, mannose-binding lectin, etc.
Lifestyle/nutrition:

Female gender
In children or if symptoms in adults have persisted since childhood: Birth by cesarean section, not breastfed, growth retardation