Gut Instincts

Our intestines do a lot of work without complaint. When they do complain, what does it mean?

By Tony Dajer|Saturday, September 01, 2001
RELATED TAGS: INFECTIOUS DISEASES
"Appendicitis— what else could it possibly be?" I asked.

Steve shrugged. "I'm a little worried about the pain in his flank. And that blood in his urine."

Steve is an excellent surgeon, but this time he was splitting hairs. I walked over to the patient and tapped my fist halfway up his back, left and right— where the kidneys lie. "Does that hurt, Robert?" I asked.

"No," said the muscular young man.

I walked back to confer with Steve.

"You're probably right," Steve conceded. "But let's get the CAT scan."

"C'mon, his kidneys are fine. He has appendicitis. What's the mystery?"

Since 1998, spiral CAT scans, which create more precise images than conventional CAT scans, have revolutionized the diagnosis of appendicitis. But there are some drawbacks: a cost of about $800, a possible allergic reaction to the injected material that helps create the image, and the four-to-six-hour wait for a result. Besides, good clinicians know which data to ignore. Robert's urine contained a few red blood cells per microscopic field. This is common. Unless there is intense pain indicating a kidney stone or irritation from a bladder infection, a few blood cells in the urine are meaningless.

"A 22-year-old male with diffuse abdominal pain since yesterday, now most intense in the right lower quadrant. Plus no appetite." I threw up my hands.

"How classic can you get?"

"I agree. Probably appendicitis," Steve said. "I'm just not sure." He was telling me— politely— that the sooner we got the scan, the sooner our patient would be in the operating room.

I headed back to the patient. "Robert, there's good evidence for appendicitis, but not quite enough. So we're going to get a CAT scan, OK?"

He smiled. "I'm not going anywhere."

"Still hurts, right?" I said, pressing down on the area to the right of and below his belly button.

"Comes and goes, but yes," he winced. "Still hurts."

Many ailments can mimic appendicitis: swollen lymph nodes, inflammation of the intestine, hernias, tumors, and simple viral infections, for starters. The problem is that intestines are lousy pain locators; they seldom give a distinctive pattern or quality of pain that makes diagnosis easy. Major intestinal problems often present as simply "pain all over." To make matters worse, disease in one area can present as pain in another. And appendicitis is one of the few diseases that can kill a healthy young person. That's why even four years ago it was considered prudent to operate quickly— even though the diagnosis turned out to be appendicitis in only four out of five cases. Today, however, surgeons fear that "unnecessary" operations will bring malpractice lawyers running.

Four hours later Steve's surgery resident, Tracey, called. "Intussusception," she said, her voice bright.

"What?" I stammered.

"The CAT scan shows intussusception."

"That has to be a misread on the radiologist's part," I spluttered. "Only kids get that."

"They're adamant," Tracey said.

I headed upstairs. The CAT scan of Robert's abdomen showed a glowing oblong mass.

"Abscess?" I ventured.

"Nope," Tracey answered. She slid her finger over a half centimeter. "Here. Appendix is normal."

I studied the black-and-white images of the intestine, cutting back and forth between images above and below the problem spot, which looked like one hollowed-out sausage pushing into another.

"It's at the ileocecal valve," she said.

"Makes sense," I conceded.

"Not really," she said, "but there it is."

The smooth muscle in our intestinal walls has but one mission in life: to propel dinner farther down the digestive pipe. Peristalsis, the rhythmic contraction of the intestines, is so powerful that when thwarted (as in cases of intestinal obstruction) the resulting backlash is violent projectile vomiting. Given the power of these contractions, any irregularity in the tube can act as a lead point to be dragged along into another intestinal segment. That's why intussusceptions are often one of the first signs of cancerous growths in the small intestine. The condition occurs most often at the ileocecal valve, where the final tapering bit of small intestine (the ileum) meets the beginning of the colon (the cecum). Designed to help prevent feces from flowing back up the small intestine, this small valve can sometimes get swept up in the colon's peristaltic wave, pulling more and more of the ileum after it.

Intussusception is, by and large, a disease of infancy. The peak incidence is 6 months of age, so it may have something to do with how the intestine copes with new foods. During an attack, a baby will pull up his legs (boys account, in some studies, for four fifths of all cases), scream in agony, and pass bloody stools that look like currant jelly. After 20 or 30 minutes, the pain stops as abruptly as it started, and the baby seems well again. This calm between storms has fooled many a doctor who lacks the patience to watch until the next peristaltic paroxysm hits.

Untreated, intussusception is lethal. The blood supply to the intestines flows from the mesentery, the drapery of tissue that arises from the back wall of the abdominal cavity. As the intussusceptum— the sucked-in bit of intestine— advances, the mesentery gets pulled along with it, pinching off veins and arteries. The backed-up blood makes the intestine swell, in turn strangling more blood vessels. When arterial flow stops, the intestine dies— and without an early operation, so will the patient.

In adults, the usual symptoms of intestinal obstruction are vomiting and severe abdominal pain. Robert still looked pretty comfortable.

"The surgeons were right," I began. "It wasn't appendicitis." I caught the worried look on his face. "The CAT scan didn't show any cancer either. This is really a kid's disease. Most cases occur before age 2, almost as if the intestine is still working its kinks out." I bunched the fingers of my right hand, then pushed them into a little tunnel formed by those of my left. "One piece of intestine gets pulled into another. If we don't fix it, the blood supply gets cut off. In kids we can usually reduce it with a barium enema; the fluid pumped into the colon literally pushes the advancing part back out. But in adults that doesn't work as well."

"Operation?"

"I'm afraid so," I said. What I didn't tell Robert was that about half of adult intussusceptions arise from intestinal cancers. No tumors had appeared on the CAT scan, but only a real look inside would settle the issue.

He put his arms behind his head. "Am I going to be all right?"

I held his gaze. "You'll be all right."

The next day I met Tracey in the hall.

"That thing was really stuck," she exclaimed. "We had to pull. It s We took about nine inches of ileum and cecum."

"Tumor?"

"Nothing. Some swollen lymph nodes, but certainly no good reason for a full-blown intussusception. But, hey," she added, "aren't those CAT scans great?"

Over the next five days, Robert got his strength back and began eating again. But the scar seemed to remind him that he'd lost some part of himself, and he didn't like anyone getting near it. The pathology report was a relief: just some swollen lymph nodes around the end of the ileum.

"You know, I looked it up," I told Robert. "During 30 years at the Massachusetts General Hospital, they saw all of 58 adults with intussusception. A grand total of one case was caused by enlarged lymph nodes like yours."

"I'm just a special guy."

"No one's going to believe your medical history," I pointed out.

"Not worried about that," he said, deadpan. "But what's it going to take to get them to spell it right?"
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