Diarrhea is defined as stool, or poop, that is loose or watery and you usually need to go to the toilet more often. It's very common and most cases improve by themselves within a day or two. There are many causes of diarrhea, ranging from infection, allergy, anxiety, medication side-effects or long-term conditions such as irritable bowel syndrome (IBS), Crohn's disease and ulcerative colitis.

If you have repeated indigestion or acid reflux, you may be at risk of developing gastroesophageal reflux disease (GERD). This is a general term, used to describe acid reflux, either with or without inflammation of the gullet (esophagus). In it, the corrosive acid our stomach produces to break down food moves up to the esophagus (the food pipe), where the lining is much more sensitive and so can get damaged over time. If you have GERD you typically experience heartburn, where you may feel a gnawing or burning pain in your central chest that moves up to the throat after eating. While you may have suffered indigestion before, symptoms with GERD may be much more easily triggered, more severe, and last longer after eating or drinking. It can also be the case that the usual treatments you have used before and which worked well may no longer be effective. Regular acid reflux is more common in smokers, pregnant women, heavy drinkers, the overweight or obese and people aged between 35 and 65 years old.

A deep vein thrombosis (DVT) is a blood clot that develops in a large vein, usually in the lower leg, and requires treatment to ease symptoms and prevent clots from spreading to other areas in the body. A pulmonary embolism (PE) is the most serious complication, where part of the DVT breaks off and a clot lodges in one of the blood vessels going to the lungs, blocking the blood supply. This can cause difficulty in breathing and collapse – it's a life-threatening condition that requires immediate medical attention. It’s believed that around 900,000 people in the US have a DVT or PE every year.

There are a few common causes of an itchy bottom, and we may find no cause, in which case we call it pruritus ani. Threadworms (pinworms) are very common in children but rare in adults. This is a parasite infection causing intense itching around the anus and possibly the vagina, especially at night. You might notice tiny white worms around your child’s anus or mixed in poop. In adults, hemorrhoids may be to blame. You may be able to feel one lump or more around the anus, and it may be painful when you go for a poop. You may get a few streaks of blood in the toilet bowl or on toilet tissue. These are common, and treatments are available. Infections from a fungus or yeast (thrush) can feel itchy and sore. The area will look pink, perhaps with tiny pink bumps and possibly flaky. Psoriasis can look similar but will likely be more red than pink, with a clear border, and is a more likely cause if you have psoriasis on other parts of the body. Eczema may appear around the bottom, especially if you have a tendency to it or irritation from any cream or treatments you are using, such as perfumed moisturizers, steroid creams, or ointments for anal fissures. Genital warts can appear as hard lumps around the anus and wider genital area and may be itchy. These are sexually transmitted and contagious to intimate partners. Finally, a condition called lichen sclerosus causes the skin to tighten, which can be itchy. You might see some white streaks on the affected area, making it look shiny and taut.

Irritable bowel syndrome (IBS) is a chronic condition that affects the gastrointestinal system. It causes abdominal discomfort or pain along with bloating or changes in bowel habits. Certain symptoms like bloating, trapped gas, and abdominal cramps can prove embarrassing, particularly if you have diarrhea or need to rush to the bathroom several times a day. Many suffer in silence, reluctant to go to their doctor or pharmacist to discuss such personal issues. There is no specific test to confirm IBS. Doctors can make a diagnosis based on symptoms, persisting for at least 6 months, and in the absence of other gastrointestinal conditions that could account for symptoms. Bowel habits must be altered more than a quarter of the time to meet the criteria for diagnosis. IBS is a common condition that isn’t life-threatening and that doesn’t put you at higher risk of serious conditions like bowel cancer. However, it’s a long-term condition that can be debilitating and cause significant impact on work, study, social activities, and daily tasks. It can take its toll on your mood and quality of life. Symptoms may be continuous or intermittent, with a chronic waxing-and-waning cycle that can last for years. IBS is a common condition, affecting 10 to 15% of the US population. That’s likely an underestimate, as many people don’t seek medical help. Symptoms usually start before the age of 40 years and it more often occurs in women.

Lactulose is an oral solution used to treat constipation on prescription only. It comes as a sugar-like syrup and is suitable for adults and children.

Vomiting is common in children and can happen for a number of reasons. It’s usually due to an infection in the gut – gastroenteritis – and will clear in a day or two. Occasionally, it can indicate something serious, but other signs also guide you to recognize this. Gastroenteritis can also cause diarrhea – this may appear a few hours or a day after vomiting starts – and abdominal pain or cramps. Children usually have little appetite, and they may have a mild fever. If it lasts longer than a couple of days or they are struggling to keep fluids down, it’s time to contact your doctor.

Leukemia is a type of blood cancer. Although there are different blood cells (white cells, platelets, red blood cells), leukemia generally refers to cancers that affect the white blood cells. White blood cells are essential to fight infections and build up your immune system. When the white cells don’t function as well, our immune defenses become weakened, and we are more susceptible to getting infections, and becoming more unwell from them. Leukemia is fairly common among adults, with over 60,000 new cases diagnosed in the US each year. Age is a big factor, with those aged 65-74 years being more commonly diagnosed. While not many children get cancer, leukemia is one that frequently affects them – it behaves quite differently for them, so we’ll address that elsewhere.

A heart attack, also known as myocardial infarction or coronary thrombosis, happens when a coronary artery (a blood vessel that supplies the heart with blood) that carries oxygen-rich blood to the heart is blocked. If the blood supply is completely blocked, part of the heart muscle may be starved of oxygen, can become damaged and may die. The medical name for a heart attack is an acute myocardial infarction (MI). Although having a heart attack is very serious, the chances of survival are greatly increased if you are able to get to a hospital right away. A heart attack may also refer to a problem with the rhythm of the heart – an arrhythmia – that prevents it beating in synchrony to pump blood around the body effectively. Again, this can lead to a medical emergency. What causes an MI? Certain things can put you at higher risk of an MI. Age is the biggest factor, where our arteries become less elastic as we age, and we get build-up of plaque on the inside of the arteries (a bit like lime scale in a water pipe). Plaque causes less effective flow of blood as the tube is narrower, and a piece of plaque may break off to form a clot, causing a blockage. Other conditions can accelerate this process, including diabetes, high blood pressure, abdominal aortic aneurysm, high cholesterol, obesity, excess alcohol and smoking. Your family history or ethnicity can cause early-age plaque build-up in the arteries.

Melanoma (also known as malignant melanoma) is the most serious type of skin cancer caused by sun exposure. It's serious because the cancer can spread to other organs in the body, so it needs prompt identification and treatment. You can take steps to prevent it, but also keep a watch for any moles or other skin marks that are new, changing or don't look like your other moles. Melanoma is the 5th most common cancer in the US, with almost 100,000 new cases each year. The number of cases has doubled in the last 30 years, and it can occur at any age.

Kidney cancer is one of the 10 most common cancers in the US. Known medically as renal cancer, it is more common in men than women, and it’s rare in people under the age of 50. There are several different types of kidney cancer but the commonest type is known as renal cell cancer. Others include transitional cell cancer, Wilm’s tumors, and clear cell sarcomas that only occur in children. You have two kidneys, one on either side of your tummy (your flanks) and one slightly to the back. Their job is critical in keeping us alive - they balance up the salts (sodium, potassium, and chloride) in our blood and excrete out any excess in urine. They filter out toxins in the urine and balance out fluids by making the urine more concentrated or more watery, depending on what we need. Signs that might alert you to a kidney problem are blood in the urine or a lump in one of your flanks. It’s confirmed with blood tests, urine tests, and scans.

Low blood pressure (BP), or hypotension, can cause symptoms of feeling lightheaded, dizzy, feeling a bit weak, sick, disoriented, and suffering momentary blurred vision. It can cause you to faint. It may also cause no symptoms. It’s diagnosed when a BP machine gives a reading of less than 90/60 mmHg. A healthy BP should be less than 120/80 mmHg. You might have a slightly faster heart rate (the third number on the BP machine) to make up for the low BP, in order to keep blood flowing to your vital organs.

All women aged between 21 and 65 are recommended to get cervical screening in the US. Also called a smear test or pap test, it’s a test aiming to prevent cancer rather than a test for whether you have cancer. It checks for a certain virus that can disrupt the cells of the cervix (the opening to your womb from your vagina). If you have the virus, the cells of the cervix can then be checked for any changes that could, with time, lead to cervical cancer. Rescreening is recommended every 3 years. After the age of 65 you’ll only need screening if your last test was abnormal or if you’re in a higher risk group (HIV positive, weakened immune system, exposed to diethylstilbesterol \[DES\] before birth). Cervical cancer is not one of the most common cancers, but it is common in young women, usually affecting those in their early 30s. Once you have cervical cancer, treatment can be difficult and threaten your fertility and your overall health. But it's considered 99.8% preventable, so it's worth keeping up with your cervical screenings.

We have all grown more aware of the dangers of sun exposure in recent years, with the threat of sun damage altering our appearance and the risk of skin cancer. There are different types of skin cancer, but there are some rules of thumb to follow for any mole, whether it’s new or existing. Let's take you through when to be concerned.

Hemorrhoids are common, and many refer to them as piles. They are enlarged blood vessels just inside or outside the anus and look like small red or purple lumps. You might find blood after you go for a poop (this will be bright red blood, seen on wiping or on the stool), or you can get pain and itching around the anus. For the majority of people, they cause no symptoms at all. Sometimes hemorrhoids can become thrombosed, which means they have no blood flow due to a blood clot. These are very painful and tender to touch. Hemorrhoids are not contagious and cannot be passed on.

Incontinence is the involuntary or uncontrollable leakage of urine or poop. It is called urinary, bowel, or double incontinence if both peeing and pooping are affected. It can occur because of weakening of the muscles that control these functions or from illness such as stroke, which can affect the nerves that control them. Urinary incontinence may be brought on by coughing or laughing (stress incontinence) or when you feel the urge to urinate (urge incontinence). Incontinence is diagnosed when it has happened regularly, not just once. Muscle exercises may help train the muscles to reduce incontinence. Medication may also help control symptoms of urinary incontinence.

Coronary artery disease (CAD) is a form of coronary heart disease (CHD) and is where blood flow to the heart muscle is slowed down or blocked, reducing the amount of oxygen available for the heart to function normally. The typical cause of CAD happens gradually over many years, where the walls of the heart arteries slowly become ‘clogged up’ with deposits of fatty substances, called atheroma. This process is called atherosclerosis and the atheroma is often known as ‘plaques’. These plaques can build up and cause the vessels to become inflamed and damaged, causing a partial or complete blockage, and conditions like angina, heart attacks and heart failure may follow as a result. CAD develops over a lengthy period of time – usually years or decades – which can mean it takes time before symptoms develop. Some damage can be repaired with lifestyle changes and medication, surgery may be suggested in some cases, but some damage may be permanent. Many factors can cause atherosclerosis including high cholesterol levels, diabetes, obesity, high blood pressure, smoking and drinking too much alcohol.

Cholesterol is a fatty substance that is present in your blood. High cholesterol, also known as hypercholesterolemia, occurs when there are raised levels in your body. Fatty substances build up in your blood mainly due to diet and lifestyle choices. Eating unhealthy fatty foods and not exercising enough puts you at risk of developing high cholesterol. If you smoke or drink alcohol or are overweight, your risk increases further. Too much cholesterol can cause a blockage in the blood vessels. There is a link between the increasing blockage of blood vessels and a higher risk of having a heart attack or a stroke. If someone in your family has high cholesterol, then you are also more likely to suffer from it. There are no symptoms of high cholesterol, the only way to confirm this is with a blood test.