Current status of small bowel radiography.

BACKGROUND: In the past, small bowel examinations were usually ordered for the sake of "completeness." As a result, small bowel radiography was performed casually and without attention to detail. This review examines pertinent clinical issues and the recent contribution of small bowel radiography to the evaluation and management of the patient with suspected small bowel disease. Recommendations for the clinical utilization of small bowel radiography are discussed. METHODS: Analysis of pertinent citations addressing valid indications for, and technique of, small bowel radiography from 1980 to July 1995 through a computerized bibliographic search (Medline and Current Contents). RESULTS: Accepted clinical indications for small bowel radiography include (1) unexplained gastrointestinal bleeding, (2) possible small bowel tumor, (3) small bowel obstruction, (4) Crohn disease, and (5) malabsorption. The current literature reflects the limitations of the conventional small bowel follow-through, various modifications to improve its clinical yield, the important contribution of enteroclysis in the workup, and subsequent management of patients with possible small bowel disease. A controversy in the radiology literature exists as to whether to use the small bowel follow-through or enteroclysis as the primary method of examining the small bowel. CONCLUSION: The thoughtful selection of patients by clinicians for small bowel radiography is essential to make radiologic evaluation cost effective. The incidence of disease of the small intestine is low and is associated with nonspecific symptoms. Because of the inherent difficulty of visualizing numerous loops of an actively peristalsing bowel, a reliable imaging method is needed that not only detects small or early structural abnormality but also accurately documents normalcy. The yield of information provided by enteroclysis and its high negative predictive value suggests that it should be the primary method for small bowel examination. The "overhead"-based conventional small bowel follow-through should be abandoned. The "fluoroscopy"-based small bowel follow-through augmented when necessary by the peroral pneumocolon or the gas-enhanced double-contrast follow-through method is an acceptable alternative when enteroclysis is not possible.

Discomfort during double-contrast barium enema examination: a placebo-controlled double-blind evaluation of the effect of glucagon and diazepam.

PURPOSE: To evaluate the effectiveness of glucagon and diazepam as compared with placebo in decreasing abdominal discomfort in patients during double-contrast barium enema examination. MATERIALS AND METHODS: Thirty-six men (n = 9) and women (n = 27) aged 21-62 years with "a lot or terrible discomfort" during double-contrast barium enema examination were randomized into double-blind groups of 12 patients each at the onset of examination. Each group received a placebo, glucagon (1 mg), or diazepam (5 mg) intravenously. Discomfort was scored on a four-point scale by the patients. RESULTS: Repeated measures analysis of variance findings indicated that those who received an active drug reported significantly (P = .001) greater relief of discomfort. Discomfort scores improved, on average, 2.2 in the glucagon, 2.0 in the diazepam, and 1.2 in the placebo groups. Colonic spasm did not correlate with abdominal discomfort. CONCLUSION: Discomfort during double-contrast barium enema examination can be statistically significantly diminished with a hypotonic agent or a sedative.

Nasointestinal tube for decompression or enteroclysis: experience with 150 patients.

The initial clinical experience with the use of a triple lumen long tube designed for gastrointestinal decompression and enteroclysis is reported in 150 patients. Based on clinical observations, this tube is effective in suctioning retained gastric and intestinal fluid but requires frequent irrigation of the sump port for effective decompression of distended small bowel. In all patients with a preexisting nasogastric tube, the replacement by the decompression/enteroclysis tube was considered more comfortable by the patients. Successful placement of the tube in the jejunum was achieved in 147 of 150 consecutive patients on the initial attempt. The use of this tube obviates dual intubations for decompression and enteroclysis, the attendant discomfort on the patient, and it expedites subsequent performance of enteroclysis if needed. The complications reported with other long intestinal tubes were not observed with this device.

Obstruction of the small intestine: accuracy and role of CT in diagnosis.

The reliability of abdominal computed tomography (CT) in the assessment of varying degrees of small bowel obstruction (SBO) was evaluated by using results at enteroclysis and clinical outcome as standards of reference. A blinded retrospective analysis was performed of the studies of 55 patients who underwent both CT and enteroclysis in the course of assessment for suspected SBO. Nine patients had no obstruction, 40 patients had obstruction due to adhesions, and six patients had tumor-related obstruction. CT results were used to identify correctly 63% (29 of 46) of those who had SBO and 78% (seven of nine) of the patients who did not. The overall accuracy of the CT interpretations to help establish diagnosis was 65% (36 of 55). When obstructions were classified into low- and high-grade partial obstruction, CT results could be used to identify correctly 81% (17 of 21) of high-grade SBOs and 48% (12 of 25) of low-grade SBOs. The procedure yielded two false-positive and 13 false-negative results for patients with low-grade obstruction, revealed masses in all six cases with tumor-related obstruction, and helped predict the correct cause in all true-positive cases.

Crohn disease of the small intestine: accuracy and relevance of enteroclysis.

The accuracy and clinical relevance of enteroclysis in the evaluation of 138 patients referred for enteroclysis for suspected Crohn disease of the small intestine are reported. The original prospective interpretations of enteroclysis results were assessed after a clinical follow-up period of 2 or more years. With all patients considered, enteroclysis had a sensitivity, specificity, and accuracy of 100%, 98.3%, and 99.3%, respectively, with only one false-positive diagnosis and no false-negative diagnoses. Thirty-one percent (n = 43) of the patients had lesions of early Crohn disease. All patients who required surgery (n = 23) had advanced lesions of the disease, according to enteroclysis criteria. Clinical evidence of Crohn disease did not develop in the 58 patients in whom enteroclysis revealed no abnormality. There were no complications related to the procedure. It is concluded that enteroclysis is an accurate method for diagnosis and exclusion of Crohn disease of the small intestine and provides detailed structural information relevant to appropriate management of the disease.

Evaluation of the small intestine by enteroclysis for Crohn's disease.

We reviewed the records of 100 consecutive patients referred for enteroclysis by gastroenterologists because of suspected Crohn's disease of the small bowel to assess the clinical utility of the information obtained by this method. More than one-third of the patients in the study group had subtle lesions of early Crohn's disease, all patients who required surgery had severe disease by radiologic criteria, and none of the 34 patients clinically suspected of having Crohn's disease of the small bowel in whom the enteroclysis was normal developed Crohn's disease in two or more years of clinical follow-up. Enteroclysis provides gastroenterologists with accurate and detailed structural information relevant to the appropriate management of the disease and in our hands is a reliable test for excluding Crohn's disease of the small bowel.

Factors in the diagnostic delays of small bowel malignancy.

The overall survival from primary malignancies of the small intestine has not changed over more than four decades. This generally is ascribed to delays in establishing the diagnosis and the advanced stage of the disease when treatment is begun. There has been no critical analysis of these delays. To answer these questions, we reviewed the records of all patients diagnosed with small bowel malignancy from 1967 to 1988 at the Methodist Hospital of Indiana. The onset and duration of symptoms, first medical consultation, time of performance of diagnostic procedures and surgery were verified in 77 patients with histologically confirmed small bowel malignancies. The longest delay occurs from the time medical help is sought to the time the diagnosis is made, not from the onset of symptoms to the first medical consultation. The small bowel should always be considered as a source of unexplained, persistent subtle abdominal symptoms.

The role of the physician in the late diagnosis of primary malignant tumors of the small intestine.

Survival from primary malignancies of the small intestine has not improved during the last four decades. One reason for this is the advanced stage of disease at the time of surgery. In order to determine why diagnosis is made late, we reviewed the records of all patients with small bowel malignancy diagnosed between 1967 and 1988. The time from the onset of symptoms to the first medical contact and the time from medical contact until diagnosis were evaluated in 77 patients. The average delay in diagnosis attributable 1) to the patient failing to report symptoms was less than 2 months, 2) to the physician not ordering the appropriate diagnostic test was 8.2 months, and 3) to the radiologist failing to make the diagnosis was 12 months. Thus, the major delay in diagnosis was after medical help was sought and not from the onset of symptoms to first medical consultation. Physicians must increase their sensitivity to the subtle but persistent symptoms that necessitate a small bowel evaluation.

Primary malignant tumors in the small bowel: a comparison of the small-bowel enema and conventional follow-through examination.

Of 71 patients diagnosed with primary mesenteric malignant tumors in the small bowel over a 21-year period in a community/teaching hospital, 14 underwent small-bowel follow-through, 16 underwent small-bowel enema (enteroclysis), and four patients underwent both studies preoperatively. In a retrospective study, the sensitivity of both the small-bowel enema and the conventional small-bowel follow-through examination were compared on the basis of the original radiologic interpretation. The studies were ordered by clinicians in a clinical setting. Results of the small-bowel follow-through were abnormal in 11 of 18 patients for a sensitivity of 61%, and small-bowel enema showed abnormalities in 19 of 20 patients for a sensitivity of 95% (p = .0165). The actual tumor was shown in six (33%) of 18 small-bowel follow-through studies and in 18 (90%) of 20 small-bowel enemas (p = .0005). In four patients, normal findings on conventional small-bowel follow-through were followed by abnormal findings on small-bowel enema done for the same reason. This experience suggests that the small-bowel enema is more sensitive than the conventional follow-through examination for the detection of small-bowel cancers.

Healing and recurrence of active duodenal ulcer with nizatidine.

Nizatidine, a new H2-receptor antagonist for treatment of duodenal ulcer disease, was evaluated in a unique two-phase, placebo-controlled, randomized, double-blind, multicenter clinical trial. Patients received either 150 mg nizatidine twice daily or placebo for 4 weeks (phase I). If ulcer healing did not occur during phase I, patients were randomly reallocated to receive either 150 mg nizatidine twice daily or placebo for an additional 4 weeks (phase II). Patients with a healed ulcer continued on the same therapy. All patients were endoscoped at week 8. Healing rates at week 2 were 93 of 265 (35%) nizatidine-treated patients and 55 of 260 (21%) placebo-treated patients (p less than 0.001); at week 4, healing rates were 198 of 259 (76%) nizatidine-treated patients and 95 of 243 (39%) placebo-treated patients (p less than 0.001). In phase II, ulcer healing occurred in 46 of 86 (53%) nizatidine-treated patients and in 23 of 90 (26%) placebo-treated patients (p = 0.002). In patients who had a healed ulcer at previous endoscopies, 18 of 178 (10%) nizatidine-treated patients and 10 of 81 (12%) placebo-treated patients had a recurrence of duodenal ulcer. Smokers who had histories of previous ulcers were more likely to have an early recurrence.

The laboratory response to glucagon dosages used in gastrointestinal examinations.

Laboratory studies occasionally are necessary for patients who have undergone hypotonic gastrointestinal examinations. To ascertain the effects of glucagon on these patients, we determined the biochemical and hematologic responses to doses of 0.25-2 mg of glucagon in a double-blind crossover study. When glucagon was given intravenously or intramuscularly in increasing doses, serum values for glucose and insulin increased linearly up to 1 mg with a slight decrease at 2 mg. After intravenous and intramuscular administration of glucagon, the white blood cell count and the percentage of neutrophiles and bands increased, and the percentage of lymphocytes decreased. Reports of side effects included one each of nausea and mouth dryness after intravenous glucagon and four reports of nausea and one of mouth dryness after intramuscular glucagon. No changes in the pulse and blood pressure could be attributed to glucagon administration.

Small bowel radiography: how, when, and why?

Since the advent of endoscopy for evaluating the upper and lower gastrointestinal (GI) tracts, it has become clear that only in the small bowel does barium radiography remain unchallenged. Regrettably, barium examination of the small bowel has traditionally been regarded by many radiologists as a study of minor importance. Small bowel follow-through techniques and enteroclysis methods differ in their diagnostic purpose, potential, and methods of performance. This review examines in detail the spectrum of barium examination techniques currently available for evaluating the small bowel. The benefits of enteroclysis in the majority of clinical situations requiring contrast examination of the small bowel are stressed. Radiologists play the crucial role in the diagnostic evaluation of the small bowel and should strive to refine and advance the accuracy of small bowel radiography.

Treatment of duodenal ulceration in the United States.

Nizatidine, a new H2-receptor antagonist for the treatment of duodenal ulcer disease, was compared with placebo in a dose-response, double-blind, parallel, multicenter clinical trial. Patients were randomly allocated to receive either nizatidine (25 mg b.i.d., 150 mg b.i.d., or 300 mg at bedtime) or placebo. At the end of 4 weeks, patients whose ulcer had not healed were randomly reallocated to receive either the nizatidine 150 mg b.i.d. dosage regime or placebo for an additional 4 weeks. Nizatidine doses of 300 mg at bedtime and 150 mg b.i.d. demonstrated similar healing frequencies. Both of these doses were statistically significantly superior in ulcer healing to the nizatidine 25 mg b.i.d. dose and to placebo at the end of 4 weeks. Patients randomly reallocated to receive nizatidine had significantly greater healing rates than patients randomly reallocated to receive placebo. In summary, nizatidine given as a single evening dose of 300 mg or as 150 mg b.i.d. proved to be equally safe and effective in the healing of active duodenal ulcers.

Nizatidine as maintenance therapy of duodenal ulcer disease in remission.

A new H2-receptor antagonist, nizatidine (150 mg h.s.), was compared with placebo as maintenance therapy in a randomized, parallel, double-blind, one-year study of 513 patients with recently healed duodenal ulcer. Endoscopies were performed at 0, 3, 6, and 12 months and at unscheduled times if symptoms of active peptic ulcer disease were present. Cumulative ulcer recurrence rates for nizatidine and placebo were 13 versus 40% at 3 months, 24 versus 57% at 6 months, and 34 versus 64% at 12 months. The differences were significant (p less than 0.001) at each treatment period. Smokers in both treatment groups had significantly greater recurrence rates than non-smokers. Symptoms of peptic ulcer disease were significantly less in nizatidine-treated patients in the first 3 months of treatment. Adverse events, including those related to peptic ulcer disease, occurred more frequently in placebo-treated patients. Nizatidine proved to be safe and effective in preventing recurrences of duodenal ulcer.

A pharmacokinetic profile of nizatidine in man.

In this report, the pharmacokinetic, pharmacodynamic, and hormonal effects of nizatidine are reviewed in healthy volunteers and in patients with renal or hepatic impairment. The absolute oral bioavailability of nizatidine exceeded 90%; the half-life (t1/2), plasma clearance (Clp), and volume of distribution (Vd) of iv nizatidine were 1.3 h, 461/h, and 1.21/kg, respectively. Within 16 h of dosing volunteers with nizatidine, more than 90% of the administered dose was recovered in urine as parent drug and metabolites; unchanged nizatidine accounted for 65 and 75% of the recovered substances, after oral and intravenous administration, respectively. Renal impairment decreased the elimination of nizatidine and dosage reductions are recommended for patients with creatinine clearance (Clcr) less than 50 ml/min/m2. Nizatidine suppressed gastric acid secretion produced by sham meals, protein meals, or pentagastrin; its antisecretory activity was dose and concentration dependent. Nizatidine was three times more potent than cimetidine. Nizatidine, after oral or iv administration, did not alter hormone concentrations in plasma.

State-of-the-art barium examination in opportunistic esophagitis.

This report presents a comparison of state-of-the-art esophagography and endoscopy in the diagnosis of pathologically proven esophagitis. The modern multiphasic esophagogram is shown to have a sensitivity of 92% for the detection of opportunistic esophagitis in the immunocompromised patient. State-of-the-art esophagography provides a sensitive and inexpensive method for investigating patients in whom opportunistic esophagitis is suspected and for monitoring their response to therapy.