Certain medications are likely to cause gastrointestinal symptoms. Opioids and oral iron supplements are particularly associated with constipation, while NSAIDs, antiplatelets and anticoagulants put patients at risk of GI bleeding. Chemotherapeutic agents are particularly associated with nausea and vomiting.

In a patient with GI bleeding or systemic symptoms such as fevers, lethargy and weight loss, always ask about family history of cancer. Gastrointestinal malignancies include oesophageal, gastric, pancreatic and colorectal cancers.

In patients with jaundice / unexplained liver disease, ask about a family history of haemochromatosis, Wilson's disease and alpha-1 antitrypsin deficiency.

In patients with suspected inflammatory bowel disease or coeliac disease, ask about a family history of autoimmune conditions. This may include IBD, rheumatoid arthritis, systemic lupus erythematosus or multiple sclerosis.

In patients with a suspected infective gastroenteritis, ask about recent travel or any recent dietary changes. 

In patients being worked up for liver transplant, the social history becomes an even more vital part of decision making. Such patients require a significant level of physical, social and psychological support and it is important to ensure that the patient has these in place prior to considering these interventions. This may include ensuring that they have someone to drop them off to appointments; that they are likely to take their medications regularly; and that they are unlikely to do anything that would put them at risk such as returning to alcohol.

Take a detailed smoking history: identify how many years the patient has smoked for, how many they smoked per day, and how long since they quit (if applicable. Smoking is a risk factor for gastric, colorectal and pancreatic cancer. 

Finally, ask about recreational drug use, and particularly intravenous drug use. IV drug use is associated with blood-borne viral infections including hepatitis B and C.