Although each of the clinical entities associated with irritable bowel syndrome (IBS) in childhood can and should be treated individually, they all share a common pathogenetic mechanism - spasm of the rectum. Therefore, any therapeutic approach that relieves rectal spasm would likely play a helpful role in managing any of the conditions. The most acute troublesome symptoms which result from this spasm are colic in infants and recurrent abdominal pain (RAP) in older children. A direct procedure to relieve spasm dramatically is to insert a device which would spread apart the rectal walls and enlarge the lumen. The device could be a glycerin suppository or a greased thermometer. If these are not long enough for older children, a rectal tube could be substituted to effect opening of the rectum. Distension of the rectum by an enema or use of a stimulant suppository may serve as useful alternatives.
Effective relief for rectal spasm may also be achieved by applying heat to the abdomen. Placing infants or older children in a warm bath for 15 to 20 minutes or applying a heating pad to the abdomen for a similar period is often successful in relieving rectal spasm. Appearance of gas bubbles in the bath water is evidence of colon decompression by passage of trapped flatus. Less pain is usually the result followed by its ultimate disappearance.
The pharmacologic treatment of rectal spasm is unrewarding. Prescription of various antiperistaltic, anticholinergic, and parasympatholytic agents is widespread but ineffective both in laboratory studies and in clinical situations. Phenothiazine derivatives which tend to relieve spasm in the upper small bowel are also ineffective in colonic spasm. The successful use of small doses of ethanol in the infant with colic does not justify general recommendation for prescription of this undesirable substance to older children with IBS.
Although quick relief of rectal spasm and abdominal pain is extremely important to the acutely uncomfortable patient, an effective long range regimen which would minimize its recurrence among patients with IBS would be of more lasting value. If Apley was correct in his evaluation that "little bellyachers grow up to be big bellyachers" and IBS is a hereditary familial condition involving lifelong disturbed colonic responses to various stresses and other stimuli, might not an effective change in the pattern of these responses be more favorable than any other treatment? The answer at this time must be guarded and somewhat circumspect, not because the end is unjustified, but rather because we have no clear means to that end. Certainly, the genetic and pathophysiologic bases of colonic motility disturbance are too poorly understood to develop an effective approach to the problem at those levels.
The long range management that appears to be most useful for diminishing or preventing IBS associated symptoms is the development of regular bowel habits. This approach will not improve symptoms of infantile colic or toddler diarrhea, but it is useful in older individuals. Regularity of habit tends to reduce distal spasm, and the most successful patterns of training use conditioning. Despite slight differences in conditioning techniques used at different ages or in association with varying chief complaints, certain common features exist in all regimens.
Ritients begin management with an enema to eliminate any unusually large fecal accumulations. They are then treated with stimulant or lubricant laxatives during which time the patients are titrated to sufficient dosages to ensure regular and easy passage of one to two stools daily.
In those patients with rectums of normal size, attempts should be made to develop a regular bowel habit after a particular meal each day, usually breakfast. Once this schedule is established the laxative is gradually withdrawn and the conditioned response is relied on for daily evacuations. The primary physician should be constantly supportive of patients and their parents to ensure successful continuation of the daily evacuation. This support also minimizes the anxiety which may be provoked by sporadic symptom recurrences and lead families to misinterpret the causes of symptoms.
Some patients with chronic stool withholding due to distended rectums are not likely to be successful in the conditioning phase of management which permits reduction in laxative dosage. For these patients, treatment with stimulant laxative should be ongoing.
Diet generally does not play a major role in these conditions, except in a limited number of patients with specific food intolerances. The multiple formula changes which are regularly tried in the treatment of infantile colic or recurrent toddler diarrhea are not indicated. The restricted diets which are sometimes used in such children often initiate or perpetuate the difficulty. These children should eat normal balanced diets that are not limited by unnecessary restrictions. They should also not be strained by the addition of specific materials, such as extra fluids to avoid dehydration.
Although lactose restriction may be useful in patients with RAP, the number of children who benefit from this restriction is limited. Since adult lactase insufficiency is hereditary and does not become symptomatic until late in childhood, the diagnosis should not be generally entertained in younger children. Milk products should not be restricted in any child's diet unless one or both parents know that they suffer from lactose intolerance and require treatment.
A clear source of pain and other symptoms of IBS is the ingestion of cold fluids and foods. Cold both increases peristalsis and induces rectal spasm, and should be avoided. In fact, the difficulty some patients have with milk intake is due more to the temperature at which it is ingested than to its protein, lactose, or fat content.
A final subject of discussion of the role of food in IBS relates to the use of bulk in the diet. The mechanism by which bulky carbohydrates, specifically bran, are digested allows these complex substances to pass largely unchanged to the colon, where bacterial activity ferments and digests them. The resultant small molecules draw fluid into the colon. If sufficient volume of soft colonic contents results from this osmotic activity, subsequent passage of the bulky loose intestinal contents occurs. However, if the osmotic activity generated is insufficient to increase bowel water enough to induce a bowel movement, the addition of bran to the diet is not only in vain, but may even be counterproductive. The intestinal gas generated by insufficient amounts of bran leads to increased bloating and flatus without evacuations. Abdominal pain may persist or actually intensify. Small amounts of dietary brain are thus worse than no bran at all. The primary physician must be careful to follow through on prescription of food "additives" such as bran by paying attention to the quantity, quality, and effect in each individual patient.
Finally, the role of emotional therapy for patients and parents deserves some general remarks. There are some parents who require ongoing help from a psychotherapist or child guidance expert because the underlying problem has so disturbed the parent-child relationship that the IBS symptoms are worsened from the resultant distortions in interpersonal behavior. In selected cases, the child (patient) may also require this level of professional emotional therapy, especially the teenager. However, for the vast majority of patients ongoing emotional support by the primary physician is sufficient without need to resort to more intensive psychotherapy. In general, various types of psychotherapy, whether psychoanalytic, environmentally manipulative, eclectic, given individually or in groups, are not indicated and are unsuccessful in modifying the course of IBS.