Rare diseases · Sign or symptom
Diarrhea
Watery stool
HP:0002014
What it means
Abnormally increased frequency (usually defined as three or more) loose or watery bowel movements a day.
In everyday care
Most people with this sign do not have a rare disease — it appears in common conditions far more often. These general reference pages cover the same topic:
Rare diseases that can present with this209
Very common80–99%
33- Acute adrenal insufficiency
- Addison disease
- Autosomal non-syndromic agammaglobulinemia
- Carney triad
- Cholera
- Congenital enterocyte heparan sulfate deficiency
- Congenital sucrase-isomaltase deficiency
- Cronkhite-Canada syndrome
- Cystic fibrosis-gastritis-megaloblastic anemia syndrome
- Dracunculiasis
- Ebola hemorrhagic fever
- Enteric anendocrinosis
- Erythroderma desquamativum
- Familial gestational hyperthyroidism
- Familial hyperthyroidism due to mutations in TSH receptor
- Foodborne botulism
- Glucose-galactose malabsorption
- Hereditary folate malabsorption
- Hyperinsulinism due to short chain 3-hydroxylacyl-CoA dehydrogenase deficiency
- Juvenile polyposis of infancy
- Late-onset isolated ACTH deficiency
- Lujo hemorrhagic fever
- Malakoplakia
- MPI-CDG
- Non-syndromic agammaglobulinemia
- Rabies
- Reactive arthritis
- Reticular dysgenesis
- Stevens-Johnson syndrome
- Thiamine-responsive megaloblastic anemia syndrome
- Tumor necrosis factor receptor 1 associated periodic syndrome
- Whipple disease
- Zollinger-Ellison syndrome
Common30–79%
46- Acute liver failure
- Acute radiation syndrome
- Adult intestinal botulism
- Aggressive systemic mastocytosis
- Alternating hemiplegia of childhood
- American trypanosomiasis
- ATTRV30M amyloidosis
- Autoimmune lymphoproliferative syndrome due to CTLA4 haploinsuffiency
- Autosomal dominant severe congenital neutropenia
- Beta-ketothiolase deficiency
- Blue diaper syndrome
- Cap polyposis
- Cholesteryl ester storage disease
- Cockayne syndrome type 1
- COG7-CDG
- Colchicine poisoning
- Congenital hyperinsulinism due to HNF4A deficiency
- Crimean-Congo hemorrhagic fever
- Cutaneous mastocytoma
- Cytomegalovirus disease in patients with impaired cell mediated immunity deemed at risk
- Diffuse cutaneous mastocytosis
- Eosinophilic gastroenteritis
- Ethylmalonic encephalopathy
- Familial adenomatous polyposis
- Familial glucocorticoid deficiency
- Familial hypoaldosteronism
- Familial Mediterranean fever
- Fructose-1,6-bisphosphatase deficiency
- Glucagonoma
- Graft versus host disease
- GRFoma
- Hereditary angioedema type 1
- Hereditary angioedema with C1Inh deficiency
- Hereditary arginine vasopressin deficiency
- Hereditary ATTR amyloidosis
- Hereditary fructose intolerance
- Hyperimmunoglobulinemia D with periodic fever
- Immune-mediated thrombotic thrombocytopenic purpura
- Immunodeficiency by defective expression of MHC class II
- Infection-related hemolytic uremic syndrome
- Inhalational botulism
- Intestinal botulism
- Isolated mesenteric vein thrombosis
- Kawasaki disease
- Lysinuric protein intolerance
- Lysosomal acid lipase deficiency
The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.
Part of the broader category
Also called: Diarrhoea
Tracking symptoms like this for someone? Eleplan keeps symptoms, diagnoses, medications and every specialist in one plan.
Start free with EleplanThis page uses the Human Phenotype Ontology (2026-06-23) — Human Phenotype Ontology Consortium, hpo.jax.org. Disease associations from Orphanet (INSERM), CC BY 4.0. Content is educational and is not medical advice.