Coffee ground vomitus refers to a particular appearance of vomit. Within organic heme molecules of red blood cells is the element iron, which oxidizes following exposure to gastric acid. This reaction causes the vomitus to look like ground coffee. Coffee ground vomitus is a sign of possible upper gastrointestinal bleeding but studies show that it may not require urgent endoscopy. Causes
Esophagitis, esophageal varices, gastritis, cirrhosis or gastric ulcers for example, may bleed and produce coffee-ground vomitus. When unaccompanied by melena, hematemesis or a fall in hemoglobin with corresponding urea rises and creates an unstable reaction, and other causes of coffee ground vomitus need to be elucidated; for example, gastric stasis, bowel obstruction or ileus, that can cause oxidised food material to be vomited. Vomiting iron supplements can also mimic coffee grounds to the untrained eye.Diseases such as Ebola, yellow fever, viral hepatitis, haemophilia B, fatty liver disease and cancers of stomach, pancreas, esophagus and, rarely, retrograde jejunogastric intussusception might also be the reason behind coffee-ground vomitus.When attributed to peptic inflammation, use of nonsteroidal anti-inflammatory drugs (NSAIDs) and selective serotonin reuptake inhibitors (SSRIs) are commonly implicated. These drugs can interfere with the stomachs natural defenses against the strongly acidic environment, causing damage to the mucosa that can result in bleeding. Therefore, it is recommended that these class of drugs be taken with food or on a full stomach. Other causes of inflammation may be due to severe gastroesophageal reflux disease, Helicobacter pylori gastritis, portal hypertensive gastropathy or malignancy.
Brachydactyly type D, also known as short thumb or stub thumb and inaccurately referred to as clubbed thumb, is a condition clinically recognised by a thumb being relatively short and round with an accompanying wider nail bed. The distal phalanx of affected thumbs is approximately two-thirds the length of full-length thumbs. It is the most common type of brachydactyly, or shortness of digits, affecting approximately 2–3% of the population, and is associated with the HOXD13 gene, located on chromosome 2q31.1

Physiology
Brachydactyly type D is a skeletal condition which exhibits a partial fusion or premature closing of the epiphysis with the distal phalanx of the thumb, according to Goodman et alia (1965). J.K. Breithenbecher (1923) found that distal phalanges of stub thumbs were one-half the length of full-length thumbs, while R.M. Stecher (1957) claimed that it is approximately two-thirds. The condition may either be unilateral (affecting one thumb) or bilateral (affecting both). Genetics
A genetic trait, brachydactyly type D exhibits autosomal dominance and is commonly developed or inherited independently of other hereditary traits. The condition is associated with the HOXD13 gene, which is central in digital formation and growth.Various other studies supported an autosomal dominant pattern with reduced penetrance. Hereditary trait
A 1965 scientific study in Israel found that 3.05% of Palestinians in Israel had one or two stub thumbs, compared with 1.57% among Ashkenazi as well as non-Ashkenazi Jews.