The Small Bowel

Changes in gastric mucosal histamine and prostaglandin E2-like activities in relation to portal somatostatin following small bowel resection in guinea-pigs

The effects of 85% intestinal resection on the portal somatostatin (SLI) gastric mucosal histamine (HA) and prostaglandin E2 (PGE2)-like activities were studied in guinea-pigs. A considerable increase in gastric mucosal HA-like activity of guinea-pigs subjected to small bowel resection (189.9 +/- 15.0 ng/g tissue) was measured in comparison to control values (42.9 +/- 6.3 ng/g tissue) (p < 0.001). The mean tissue PGE2-like activity in the sham operated group was 1636.9 +/- 128.8 ng/g tissue, whereas in the test group it was 650.5 +/- 59.3 ng/g tissue. After 85% small bowel resection a significant fall in portal and systemic venous SLI values was observed (T = 0, p < 0.05). Thus, the small bowel seems to be a major source of the increase of gastric mucosal HA-like activity and the decrease in PGE2-like activity.

Patients with a high jejunostomy do not need a special diet

Absorption from a chemically defined liquid feed consisting of small peptides, oligosaccharides, and little fat (half medium-chain triglycerides) was compared with that from a feed of whole protein, polysaccharides, and long-chain triglycerides in 7 patients with less than 150 cm of jejunum ending in a stoma. Comparisons of absorption from three solid food diets varying in their fiber and fat content but containing equal amounts of nitrogen and minerals were also made in 4 of the patients. There were no consistent differences between the two liquid or three solid-food diets in percentage of calorie, nitrogen, or fat absorption. The absolute loss of fat depended on the fat intake, but larger losses did not appear detrimental. A liquid diet consisting of peptides, oligosaccharides, and medium-chain triglycerides is not more beneficial than a polymeric diet in patients with a high jejunostomy. A liberal attitude is appropriate toward the fat and fiber content of the diet. Electrolyte supplements, especially sodium and magnesium, are often needed.

The effect of a reversed ileal segment and artificial valve on intestinal transit and absorption following colectomy and low ileorectal anastomosis in the dog

The main problem facing patients with ulcerative colitis after mucosal proctectomy and ileo-anal anastomosis (MP + IAA) is severe frequency of bowel action. Although the addition of a pelvic reservoir can improve matters, some patients still complain of this problem. In an attempt to slow transit, enhance absorption and improve function, we investigated the effects on these parameters of a reversed ileal segment, an artificial valve in an animal model. Studies were conducted before and after operation. The dogs randomly underwent either colectomy and low ileorectal anastomosis (IRA) alone (control, n = 12), IRA with a 10 cm reversed loop (IRA + RL, n = 10) or IRA with an artificial valve (IRA + valve, n = 10). Operative mortality rates were similar in the groups. Mean transit time (MTT) was significantly reduced after the control operation and after IRA + RL but not after IRA + valve. In addition MTT after IRA + valve (21 +/- s.d., 3.4 h) was significantly greater than in the other two groups (control = 12.1 +/- 4.3 h, IRA + RL, 12.8 +/- 5.5 h, P less than 0.04) and frequency of bowel actions seemed less. Measurements of absorption and nutritional state, however, did not differ significantly between the groups. Thus, although the artificial valve made no difference to absorption, it did prevent the reduction in MTT that occurred after the control operation whereas the reversed loop did not. This effect might thus benefit patients who undergo MP + IAA.

Hypomagnesaemia after small bowel resection: treatment with 1 alpha-hydroxylated vitamin D metabolites

Seven patients with severe neuromuscular symptoms due to hypomagnesaemia together with hypocalcaemia following extensive resection of the small bowel were treated orally with 1 alpha-hydroxylated metabolites of vitamin D and magnesium oxide. There was a rapid response in both plasma calcium and magnesium concentrations. The mean plasma magnesium rose from 0.24 to 0.45 mmol/l with the vitamin D metabolites alone and to 0.81 mmol/l when magnesium oxide was added. The plasma calcium rose from 1.78 to 2.21 mmol/l on vitamin D alone and then remained within the normal range. This was accompanied by a rapid resolution of the neuromuscular symptoms. Such oral treatment is both acceptable to the patient and effective both for acute symptoms and in the long term to maintain plasma magnesium concentrations.

Enteral therapy in the management of massive gut resection complicated by chronic fluid and electrolyte depletion

Following combined resection of small and large bowel, fluid and electrolyte depletion may necessitate chronic intravenous therapy. We report two such patients who were dependent upon thrice weekly intravenous electrolyte infusions to maintain body weight and urine output. The patients were maintained on a diet aimed at minimizing intestinal fluid losses but nevertheless were in severe negative sodium and water balance. Metabolic studies were performed to evaluate the efficacy of oral glucose electrolyte therapy in reversing negative sodium and water balance. Fluid and electrolyte homeostasis was achieved with isotonic glucose, or glucose polymer, electrolyte sipping solutions which enabled both patients to become independent of parenteral therapy.

Malabsorption in jejunal diverticulosis treated with resection of the diverticula

Patients with jejunal diverticula usually are asymptomatic unless bacterial overgrowth within the diverticula is sufficient to cause vitamin B12 deficiency, by direct uptake of the vitamin by the bacteria, or malabsorption resulting from bacterial deconjugation of bile salts and impaired lipid digestion. The administration of broad-spectrum antibiotics usually constitutes effective treatment that suppresses bacterial flora, with surgery reserved for complications such as hemorrhage, perforation, and abscess formation, and acute or chronic intestinal obstruction. Our patient had many diverticula, and two courses of antibiotics failed to provide prolonged relief of symptoms. After surgical exploration to exclude the presence of partial intestinal obstruction or infiltrating disease of the terminal ileum, the segment of jejunum bearing diverticula was resected. Since operation the patient has remained asymptomatic, which suggests that in certain patients, even with many diverticula, surgical exploration and excision of the diverticula may be curative.