Dear Doctors: I had just started a new job when the pandemic happened. On top of the lockdowns and home-schooling our kids, I was diagnosed with IBS. My husband read there’s research that it’s caused by stress, and that makes a lot of sense to me. Can you please talk about that research?

Dear Reader: IBS is short for irritable bowel syndrome. It affects the stomach and the intestines, which are part of the gastrointestinal tract. The word “syndrome” means that IBS isn’t a disease, but rather a collection of certain types of symptoms. These can include abdominal gas, chronic bloating, constipation, diarrhea and ongoing changes to the frequency and urgency of bowel movements. Someone with IBS also often has increased sensitivity to abdominal pain. Taken together, these symptoms indicate that something has gone awry in the inner workings of the bowels.

IBS is seen in women more often than in men, and it typically arises in younger populations, generally under the age of 50. It’s fairly common, occurring in up to 15% of the population. Because the symptoms are not life-threatening, many people don’t take the time to get diagnosed. That means the percentage of people living with IBS is likely higher than the rate doctor visits may indicate.

The symptoms of the syndrome can range from mild enough to just be annoying to severe enough to interfere with daily life. Previous research into the causes of IBS has focused on unresolved abdominal infections and changes to the makeup and behaviors of gut microbiome. Now, as your husband has read, newer research has found evidence that stress and anxiety may play a role.

The study he is referring to, conducted by researchers in Tokyo, was published last fall. They found that mice who were repeatedly placed in psychologically stressful situations went on to develop gastrointestinal symptoms consistent with IBS. Although previous research has looked into stress as a trigger for IBS, those studies used physical situations to trigger that stress. In this new study, the mice were placed into situations that didn’t stress them physically, but instead caused them to feel social anxiety.

During the 10-day study, the researchers found that mice who spent 10 minutes each day in a socially stressful situation developed abnormally high levels of cortisone, the hormone associated with stress. The stressed mice also had changes to their bowel movements that are consistent with IBS, as well as increased sensitivity to abdominal pain. These changes persisted for weeks after the study concluded. The control group of mice, who did not undergo any social stressors during the study, did not have any of these physical changes.

Although this research doesn’t explain the gut-brain connection in IBS, it does suggest new ways to look into the causes of the syndrome. It also underlines the importance of lifestyle changes for people with the condition. As someone living with IBS, you should avoid using tobacco and take steps to get quality sleep. If possible, add a stress reliever like yoga, meditation, tai chi or just a daily walk outside to your daily routine.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: I went to our local pharmacy to get a flu shot for myself and also for my dad. It turns out that because he is 68 years old, he didn’t get the same vaccine as me. They gave him something called “fluad quadrivalent.” How is that different from the regular flu vaccine? Why did he need it?

Dear Reader: First, we want to thank you for taking an important step in safeguarding your health and that of your father. Flu season in the United States started early this year, and it is turning out to be particularly severe. It has resulted not only in widespread illness, but also in high rates of hospitalization. That makes getting vaccinated particularly important.

Due to age-related changes to the immune system, older adults are at increased risk of developing potentially life-threatening complications from a case of the flu. According to data collected by the Centers for Disease Control and Prevention in recent years, well over half of hospitalizations due to the flu, and up to 85% of flu-related deaths, have occurred in adults 65 and older. People of all ages who are living with underlying conditions such as diabetes, asthma, lung disease and heart disease are also at increased risk.

The good news is that this year’s flu vaccine is proving to be effective at reducing the severity of disease and decreasing the risk of hospitalization. By getting vaccinated, you and your dad are protecting yourselves, as well as the people around you.

To understand the difference between the shots you and your father received, we should first define a few terms. All flu vaccines contain something called an antigen. That’s a molecular structure found on the surface of viruses, including the influenza virus. When a virus infects the body, the antigens it contains act as an alarm bell. Their presence triggers the immune system to produce specialized proteins known as antibodies, which attack the invaders.

Flu vaccines work by teaching your immune system to recognize specific antigens. This primes the immune system to be ready with a strong protective response. Although your father got a different shot than the one you received, he did not get a different vaccine. Rather, he was given what is known as a high-dose flu vaccine. That’s a shot that contains the same antigens as the regular flu vaccine but is specially formulated to elicit a stronger immune response. At this time, several types of high-dose flu vaccines are approved for use in the U.S. Each one is formulated in a slightly different way, but all have the same effect -- that is, to rev up immune response.

The fluad quadrivalent shot that your father received contains something called an adjuvant. That’s an added compound that causes a markedly stronger immune response. Another high-dose flu shot, known as Fluzone High-Dose quadrivalent, achieves the same result by upping the quantity of antigens contained in the vaccine.

As with all flu shots, side effects can include soreness or swelling at the site of the injection, fever, muscle aches, headache or nausea. To locate a high-dose flu shot near you, visit vaccines.gov/find-vaccines.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctors: Why don’t we hear more about cryoablation as a treatment for prostate cancer? It appears to be much easier than major surgery, so it seems like it would be a good option. What does the procedure entail? I am also interested in knowing about the advantages and disadvantages.

Dear Reader: Prostate cancer is the second-most-common type of cancer in men. Only skin cancers occur more often. This type of cancer arises in the prostate gland, which is about the size and shape of a walnut and is located beneath the bladder.

Because the prostate sits amid a complex network of nerves and structures that contribute to both sexual and urinary function, removing tumors in this type of cancer can be challenging. Depending on size and specific location of the cancer and whether it has spread, prostate cancer treatment can result in urinary incontinence and loss of sexual function.

Therapies may consist of one or more approaches, including surgery, radiation, chemotherapy, hormone therapy or immunotherapy. Cryoablation, also known as cryotherapy, can also be an option in certain cases. This is a procedure in which abnormal tissues are subjected to extremely cold temperatures, which destroys the cells.

Cryotherapy is performed under either regional or general anesthesia. It may be an outpatient procedure, or it can sometimes require an overnight hospital stay. Guided by ultrasound imagery, the physician inserts thin, hollow needles, known as cryoprobes, into a specific region of the prostate gland. The cryoprobes infuse freezing gas into the cells of the prostate gland, which kills them.

There are two forms of cryotherapy for prostate cancer. One type, known as whole-prostate cryotherapy, treats the entire gland. This kills both the cancer cells and the healthy tissues. Freezing the tissues of the prostate gland often damages the nearby nerves that control erections. As a result, erectile dysfunction occurs more often after whole-prostate cryotherapy than when the gland is surgically removed.

The other type of cryotherapy, known as focal cryotherapy, targets only the cancer cells. This allows less of the healthy tissue in the prostate to be destroyed. With focal cryotherapy, the risk of the loss of sexual function is minimized, but not eliminated. This approach is typically reserved for cancers that are small, well-defined and have not spread.

In both types of cryotherapy, a catheter filled with warm saltwater is used to protect the urethra. This is the tube that empties the bladder. The catheter is left in place for several weeks after the surgery, which ensures that the patient can empty his bladder as he recovers.

You are correct that cryotherapy is less invasive than surgery. It is also less painful and has a faster recovery period. However, it is not suitable for all patients. Factors such as the size, location and typing of the patient’s cancer, as well as the size of their prostate, play a role in whether cryotherapy can be an option. It is also unclear at this time if the long-term survival rates of this approach match those of either radiation or surgery.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10960 Wilshire Blvd., Suite 1955, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)