Ask the doctors: Diarrhea is common side effect after colon surgery
Q: I was diagnosed with diverticulitis, which caused a bowel perforation. I had a sigmoidectomy, no problem, and a resection. Now I'm dealing with constant and urgent diarrhea, as well as some cramping. What can I do to combat this? It is affecting my work and my home life.
A: With diverticulitis, the small pouchlike protrusions that can form along the colon wall get inflamed or infected. These protrusions are known as diverticula. They seem to develop when a weakened area of the colon wall gives way to internal high pressure. Because each diverticulum forms a kind of cul-de-sac, fecal waste and bacteria can get trapped inside. This can cause inflammation and infection.
A perforation, like a hole or a tear, in the diverticula can allow the fecal matter passing through the colon to contaminate the abdominal cavity. To prevent a severe infection, known as peritonitis, surgeons remove the damaged portion of the colon, then surgically join the two severed ends. When the surgical site is the sigmoid colon, this is called a sigmoidectomy. While this surgery saves lives, it can lead to complications.
The colon is more than a simple tube. It's a complex and finely calibrated organ. It requires precise coordination between many systems: There are layers of muscles that animate the colon. More than 100 million neurons oversee digestion, absorption and movement. Then there are trillions of microbes that make up the gut microbiome.
There are also specialized cells that absorb water, secrete hormones and mucus, sense biochemical changes and signal immune response. The loss of even a few inches of colon can disrupt the function of all these systems together.
Diarrhea is a common side effect of a sigmoidectomy. The contents of the colon now travel a shorter and faster path from the stomach to the rectum. There are also fewer specialized cells to absorb liquids. The network of neurons in the colon, known as the enteric nervous system, has been altered.
The gut microbiome itself has also changed. These can all contribute to the inability of the remaining colon to create solid stool, to act as a reservoir for that stool and to deliver appropriate bathroom urgency signals.
The diarrhea and urgency you describe are consistent with a post-surgical condition known as low anterior resection syndrome, or LARS. It's usually associated with rectal surgery, but it can also arise after surgery on the lower colon. Treatment typically includes dietary changes to avoid inflammation, consuming soluble fiber to thicken stool, transanal irrigation and medications to slow gut motility. A physical therapy regimen with a focus on pelvic floor rehabilitation, and sometimes biofeedback, is often prescribed.
A gastroenterologist or colorectal surgeon may oversee this multidisciplinary approach. A registered dietitian and a physical therapist may also help. The loss of bowel control can cause embarrassment, limit daily activities and lead to social isolation. That means bolstering mental health is an important part of the equation. The understanding and encouragement of a support group, or one-on-one therapy, can go a long way to improving quality of life.
• Dr. Eve Glazier is an internist and associate professor of medicine at UCLA Health. Dr. Elizabeth Ko is an internist and assistant professor of medicine at UCLA Health. Send your questions to askthedoctors@mednet.ucla.edu.
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