Interactions between symptoms and motor and visceral sensory responses of irritable bowel syndrome patients to spasmolytics (antispasmodics).

AIM: to evaluate and correlate the symptomatic, motor and sensory responses to two widely used categories of spasmolytic agents in irritable bowel syndrome (IBS). METHODS: 118 patients with IBS, diagnosed by Rome II criteria and 45 healthy individuals were studied. In the IBS subjects, pain severity, as well as the sensory response to rectal balloon distention and rectal and sigmoid motility, were studied at baseline and after two weeks therapy with either oral buscopan (20 mg three times a day, n=37), a buscopan suppository (30 mg once daily, n=21), oral drotaverine (80 mg three times a day, n=30), calcium gluconate tablets (one three times a day, n=16) as a control for oral agents, or calendula suppository (once daily, n=14) as a control for those who received a suppository. RESULTS: Buscopan, whether administered as a tablet or a suppository, produced a significant reduction in pain scores among IBS patients with predominant diarrhea. No significant differences were evident among other IBS subgroups or in response to drotaverine. None of the interventions had any effect on any of the parameters of rectal or sigmoid motility studied. However, both buscopan and drotaverine led to a significant augmentation of the rectal threshold for discomfort/pain among IBS subjects with predominant diarrhea [21.78 + or - 2.8 vs 39.60 + or - 2.4 (p<0.05), 20.5 + or - 2,8 vs 36.84 + or - 3.8 (p<0.05) and 22.18 + or - 2.8 vs 36.9 + or - 2.42 (p<0.05) for oral buscopan, rectal buscopan and oral drotaverine, respectively]. CONCLUSION: We conclude that the clinical benefits of supposed spasmolytic (anti-spasmodic) agents may relate more to effects on visceral sensation than motility.

Purinergic and nitrergic junction potential in the human colon.

The aim of the present work is to investigate a putative junction transmission [nitric oxide (NO) and ATP] in the human colon and to characterize the electrophysiological and mechanical responses that might explain different functions from both neurotransmitters. Muscle bath and microelectrode techniques were performed on human colonic circular muscle strips. The NO donor sodium nitroprusside (10 microM), but not the P2Y receptor agonist adenosine 5'-O-2-thiodiphosphate (10 microM), was able to cause a sustained relaxation. NG-nitro-L-arginine (L-NNA) (1 mM), a NO synthase inhibitor, but not 2'-deoxy-N6-methyl adenosine 3',5'-diphosphate tetraammonium salt (MRS 2179) (10 microM), a P2Y antagonist, increased spontaneous motility. Electrical field stimulation (EFS) at 1 Hz caused fast inhibitory junction potentials (fIJPs) and a relaxation sensitive to MRS 2179 (10 microM). EFS at higher frequencies (5 Hz) showed biphasic IJP with fast hyperpolarization sensitive to MRS 2179 followed by sustained hyperpolarization sensitive to L-NNA; both drugs were needed to fully block the EFS relaxation at 2 and 5 Hz. Two consecutive single pulses induced MRS 2179-sensitive fIJPs that showed a rundown. The rundown mechanism was not dependent on the degree of hyperpolarization and was present after incubation with L-NNA (1 mM), hexamethonium (100 microM), MRS 2179 (1 microM), and NF023 (10 microM). We concluded that single pulses elicit ATP release from enteric motor neurons that cause a fIJP and a transient relaxation that is difficult to maintain over time; also, NO is released at higher frequencies causing a sustained hyperpolarization and relaxation. These differences might be responsible for complementary mechanisms of relaxation being phasic (ATP) and tonic (NO).

Transanal one-stage endorectal pull-through for Hirschsprung's disease in infants and children.

PURPOSE: This report presents the technique and results of transanal one-stage endorectal pull-through procedure in children with rectosigmoid lesions from Hirschsprung's disease. METHODS: Eight children aged one month to 6 years with frozen section biopsy-proven Hirschsprung's disease underwent transanal one-stage endorectal pull-through procedures during a 12-month period. A rectosigmoid transitional zone was suggested by contrast enema in 7 patients; rectal manometry was done to confirm the diagnosis in one patient. Preoperative colonic irrigation to evacuate feces out of the dilated colon was done in the hospital. Bowel preparation was the same as conventional colorectal surgery. Full-thickness rectal biopsy at 1 to 2 cm above the dentate line was submitted for pathologic diagnosis. A rectal mucosectomy dissection was started 0.5 cm proximal to the dentate lines and was extended into the intraperitoneal rectum. The muscular sleeve was divided circumferentialy at 3 to 4 cm proximal to the dentate line, exposing the intraperitoneal rectum and allowing full-thickness mobilization of the rectosigmoid colon out of the anus. Aganglionic colon segment was resected, and the normal colon was pull down to anastomose with the distal end of anorectal mucosa. RESULTS: Operating time, including taking frozen sections, ranged from 110 to 180 minutes. The length of bowel resections ranged from 9 to 25 cm. The length of hospital stay depended on the amount of fecal impaction in the colon. Older children with substantial fecal impaction required 2 weeks of preoperative saline enema. One infant needed 3 days for bowel preparation, the same as for conventional colorectal surgery. The hospital stay ranged from 6 to 7 days in children younger than 2 years and 10 to 28 days in older children. There were no intraoperative or postoperative complications related to the pull-through procedure. One case of colitis occurred in the 6-year-old child, which required rectal tube decompression one week after the operation. Seven patients passed stool within 24 hours after surgery. All patients had normal bowel movements within 3 weeks. There was no rectal cuff stricture or enterocolitis during one year of follow-up. CONCLUSIONS: Transanal one-stage endorectal pull-through operations for rectosigmoid lesions from Hirschsprung's disease can be performed successfully in all ages of children with good results, avoiding transabdominal exploration. The early postoperative enterocolitis in the older children might occur and should be treated urgently. The partial coloanal anastomosis obstruction found in older children could be treated by placing a rectal tube into the anus to decompress the dilated pull-through colon. The limitation of this approach is that retroperitoneal fixation of the descending colon could not be dissected by the transanal route.